Racemic prostaglandins of the 2-series and analogs thereof

ABSTRACT

This invention is racemic PGE 2 , racemic PGF 2 .sub.α, racemic PGF 2 .sub.β, racemic PGA 2 , racemic PGB 2 , analogs of those, and processes of making them. These compounds are useful for a variety of pharmacological purposes, including anti-ulcer, inhibition of platelet aggregation, increase of nasal patency, abortion, and wound healing.

CROSS REFERENCE TO RELATED APPLICATION

This application is a continuation-in-part of copending application Ser.No. 807,405, filed Mar. 14, 1969, now abandoned.

This invention relates to compositions of matter, and to methods andintermediates for producing them. In particular, the several aspects ofthis invention relate to racemic prostaglandin E₂ (PGE₂), racemicprostaglandin F₂ (PGF₂.sub.α and PGF₂.sub.β), racemic prostaglandin A₂(PGA₂), racemic prostaglandin B₂ (PGB₂), to the corresponding acetylenicprostaglandins, 5,6-dehydro-PGE₂, 5,6-dehydro-PGF₂.sub.β,5,6-dehydro-PGF₂.sub.β, 5,6-dehydro-PGA₂, and 5,6-dehydro-PGB₂ ; toanalogs of those prostaglandins and 5,6-dehydro-prostaglandins; toprocesses for producing racemic PGE₂, PGF₂.sub.α, PGA₂, PGB₂, thecorresponding 5,6-dehydro-prostaglandins, and the analogs thereof; andto chemical intermediates useful in those methods.

Optically active PGE₂, PGF₂.sub.α, PGF₂.sub.β, PGA₂, and PGB₂ are knownsubstances. All of those except PGF₂.sub.β have been obtained in verysmall quantities from certain mammalian tissues, for example, sheepvesicular glands, swine lung, and human seminal plasma. See, forexample, Bergstrom et al., Pharmacol. Rev. 20, 1 (1968), and referencescited therein. Optically active PGE₂ and PGF₂.sub.α have also beenobtained in small amounts by enzymatic cyclization of arachidonic acid,for example, with certain of the enzymes of sheep vesicular glands. See,for example, U.S. Pat. No. 3,296,091. Similar enzymatic cyclizations ofother unsaturated long-chain acids have been used to produce a limitedgroup of optically active PGE₂ analogs. See, for example, Struijk etal., Rec. Trav. Chim. 85, 1233 (1966) and Beerthuis et al., Rec Trav.Chim. 87, 461 (1968). Optically active PGA₂ and PGB₂ have been obtainedby dehydration of PGE₂, and optically active PGF₂.sub.α and PGF₂.sub.βhave been obtained by carbonyl reduction of PGE₂. In each case, the PGE₂used was necessarily obtained as described above. See, for example,Bergstrom et al., Arkiv Kemi, 19, 563 (1963) and Pike et al., Proc.Nobel Symposium II, Stockholm (1966); interscience Publishers, New York,p. 161 (1967)]

The above-mentioned methods for producing prostaglandins are costly anddifficult, the necessary biological materials are limited, and themethods are not adaptable to production of a wide variety ofprostaglandin intermediates.

It is the purpose of this invention to provide processes for theproduction of compounds with prostaglandin-like activity in substantialamounts and at reasonable cost. The useful compounds produced accordingto the processes of this invention comprise racemic PGE₂, racemicPGF₂.sub.α, racemic PGF₂.sub.β, racemic PGA₂, racemic PGB₂, thecorresponding 5,6-dehydroprostaglandins, and other hitherto unavailableracemic and optically active analogs thereof.

PGE₂ has the following structure: ##SPC1##

Pgf₂.sub.α has the following structure: ##SPC2##

Pgf₂.sub.β has the following structure: ##SPC3##

Pga₂ has the following structure: ##SPC4##

Pgb₂ has the following structure: ##SPC5##

Racemic PGE₂, PGF₂.sub.α, PGF₂.sub.β, PGA.sub. 2, and PGB₂ are eachrepresented by the combination of one of the above formulas and themirror image of that formula. See Nature, 212, 38 (1966) for discussionof the stereochemistry of the prostaglandins.

In formulas I, II, III, IV, and V, as well as in the formulas givenhereinafter, broken line attachments to the cyclopentane ring indicatesubstituents in alpha configuration, i.e., below the plane of thecyclopentane ring. Heavy solid line attachments to the cyclopentane ringindicate substituents in beta configuration, i.e., above the plane ofthe cyclopentane ring.

PGE₂, PGF₂.sub.α, PGF₂.sub.β, PGA₂, and PGB₂ are derivatives ofprostanoic acid which has the following structure and atom numbering:##SPC6##

A systematic name for prostanoic acid is7-[(2β-octyl)cyclopent-1α-yl]heptanoic acid.

Compounds similar to formula VI but with carboxylterminated side chainsattached to the cyclopentane ring in beta configuration are designated8-iso-prostanoic acids, and have the following formula: ##SPC7##

A systematic name for iso-prostanoic acid is7-[(2β-octyl)cyclopent-1β-yl]heptanoic acid.

Racemic prostaglandin E₂ and its analogs produced according to theprocesses of this invention are represented by the formula: ##SPC8##

wherein R₁ is hydrogen, alkyl of one to 8 carbon atoms, inclusive,cycloalkyl of 3 to 10 carbon atoms, inclusive, aralkyl of 7 to 12 carbonatoms, inclusive, phenyl, phenyl substituted with one to 3 chloro oralkyl of one to 4 carbon atoms, inclusive, or ethyl substituted in the β-position with 3 chloro, 2 or 3 bromo, or 1, 2 or 3 iodo; wherein R₂ ishydrogen or alkyl of one to 10 carbon atoms, inclusive, substituted withzero to 3 fluoro; wherein R₃ and R₄ are hydrogen or alkyl of one to 4carbon atoms, inclusive; wherein A is alkylene of one to 10 carbonatoms, inclusive, substituted with zero to 2 fluoro, and with one to 5carbon atoms, inclusive, ##STR1## and wherein ˜ indicates attachment ofthe ##STR2## moiety to the ring in alpha or beta configuration, andpharmacologically acceptable salts thereof when R₁ is hydrogen.

Racemic prostaglandin F₂ and its analogs produced according to theprocesses of this invention are represented by the formula: ##SPC9##

wherein R₁, R₂, R₃, R₄, and A are as defined above for formula VIII, and˜ indicates attachment of the hydroxy and ##STR3## moieties to the ringin alpha or beta configuration, and pharmacologically acceptable saltsthereof when R₁ is hydrogen. Included in formula IX are compoundswherein the configuration of the hydroxy and ##STR4## moieties are,respectively, α, α, α,β, β,α, and β,β.

Racemic prostaglandin A₂ and its analogs produced according to theprocesses of this invention are represented by the formulas: ##SPC10##

wherein R₁, R₂, R₃, R₄, and A are as defined above for formula VIII, and˜ indicates attachment of the ##STR5## moiety to the ring in alpha orbeta configuration, and pharmacologically acceptable salts thereof whenR₁ is hydrogen.

Racemic prostaglandin B₂ and its analogs produced according to theprocesses of this invention are represented by the formula: ##SPC11##

wherein R₁, R₂, R₃, R₄, and A are defined above for formula VIII, andpharmacologically acceptable salts thereof wherein R₁ is hydrogen.

The acetylenic prostaglandin, 5,6-dehydro-PGE₂, and its analogs producedaccording to the processes of this invention are represented by theformula: ##SPC12##

wherein R₁, R₂, R₃, R₄, and A are as defined above for formula VIII, and˜ indicates attachment of the --CH₂ --C.tbd.C--A--COOR₁ moiety to thering in alpha or beta configuration, and pharmacologically acceptablesalts thereof when R₁ is hydrogen.

The acetylenic prostaglandin, 5,6-dehydro-PGF₂, and its analogs produceaccording to the processes of this invention are represented by theformula: ##SPC13##

wherein R₁, R₂, R₃, R₄, and A are as defined above for formula VIII, and˜ indicates attachment of the hydroxy and --CH₂ --C.tbd.C--A--COOR₁moieties to the ring in alpha or beta configuration, andpharmacologically acceptable salts thereof when R₁ is hydrogen. Includedin formula XIII are compounds wherein the configuration of the hydroxyand --CH₂ --C.tbd.C--A--COOR₁ moieties are, respectively α,α, α,β, β,α,and β,β.

The acetylenic prostaglandin, 5,6-dehydro-PGA₂, and its analogs producedaccording to the processes of this invention are represented by theformula: ##SPC14##

wherein R₁, R₂, R₃, R₄, and A are as defined above for formula VIII, andindicates attachment of the --CH₂ --C.tbd.C-A-COOR₁ moiety to the ringin alpha or beta configuration, and pharamcologically acceptable saltsthereof when R₁ is hydrogen.

The acetylenic prostaglandin, 5,6-dehydro-PGB₂, and its analogs producedaccording to the processes of this invention are represented by theformula: ##SPC15##

wherein R₁, R₂, R₃, R₄, and A are as defined above for formula VIII, andpharmacologically acceptable salts thereof when R₁ is hydrogen.

Formulas VIII, IX, X, XI, XII, XIII, XIV, and XV represent PGE₂, PGF₂,PGA₂, PGB₂, 5,6-dehydro-PGE₂, 5,6-dehydro-PGF₂ , 5,6-dehydro-PGA₂, and5,6-dehydro-PGB₂, respectively, when in these formulas R₁, R₃, and R₄are each hydrogen, R₂ is pentyl, A is trimethylene, the attachment of--CH₂ --CH=CH--A--COOR₁ or --CH₂ --C.tbd.C--A--COOR₁ to the cyclopentanering is in alpha configuration, and the configuration of the side chainhydroxy is S.

With regard to formulas VIII to XV, inclusive, examples of alkyl of oneto 4 carbon atoms, inclusive, are methyl, ethyl, propyl, butyl, andisomeric forms thereof. Examples of alkyl of one to 8 carbon atoms,inclusive, are those given above, and pentyl, hexyl, heptyl, octyl, andisomeric forms thereof. Examples of alkyl of one to 10 carbon atoms,inclusive, are those given above, and nonyl, decyl, and isomeric formsthereof. Examples of cycloalkyl of 3 to 10 carbon atoms, inclusive,which includes alkyl-substituted cycloalkyl, are cyclopropyl,2-methylcyclopropyl, 2,2-dimethylcyclopropyl, 2,3-diethylcyclopropyl,2-butylcyclopropyl, cyclobutyl, 2-methylcyclobutyl, 3-propylcyclobutyl,2,3,4-triethylcyclobutyl, cyclopentyl, 2,2-dimethylcyclopentyl,3-pentylcyclopentyl, 3-tert-butylcyclopentyl, cyclohexyl,4-tert-butycyclohexyl, 3-isopropylcyclohexyl, 2,2-dimethylcyclohexyl,cycloheptyl, cyclooctyl, cyclononyl, and cyclodecyl. Examples of aralkylof 7 to 12 carbon atoms, inclusive, are benzyl, phenethyl,1-phenylethyl, 2-phenylpropyl, 4-phenylbutyl, 3-phenylbutyl,2-(1-naphthylethyl), and 1-(2-naphthylmethyl). Examples of phenylsubstituted by one to 3 chloro or alkyl of one to 4 carbon atoms,inclusive, are p-chlorophenyl, m-chlorophenyl, o-chlorophenyl,2,4-dichlorophenyl, 2,4,6-trichlorophenyl, p-tolyl, m-tolyl, o-tolyl,p-ethylphenyl, p-tert-butylphenyl, 2,5-dimethylphenyl,4-chloro-2-methylphenyl, and 2,4-dichloro-3-methylphenyl.

Examples of alkylene of one to 10 carbon atoms, inclusive, aremethylene, ethylene, trimethylene, tetramethylene, pentamethylene,hexamethylene, heptamethylene, octamethylene, nonamethylene, anddecamethylene, and isomeric branched chain forms thereof.

Examples of alkyl of one to 10 carbon atoms, inclusive, substituted withone to 3 fluoro, are 2-fluoroethyl, 2-fluorobutyl, 3-fluorobutyl,4-fluorobutyl, 5-fluoropentyl, 4-fluoro-4-methylpentyl,3-fluoroisoheptyl, 8-fluorooctyl, 3,4-difluorobutyl, 4,4-difluoropentyl,5,5-difluoropentyl, 5,5,5-trifluoropentyl, and 10,10,10-trifluorodecyl.

Examples of alkylene of one to 10 carbon atoms, inclusive, substitutedwith one or 2 fluoro, have the formulas --CH₂ CHF--, --CH₂ CF₂ --, --CH₂CH₂ CHFCH₂ --, --CH₂ CH₂ CH₂ CF₂ --, ##STR6## --CH₂ CH₂ CH₂ CHFCHF--,--CH₂ CH₂ CH₂ CH₂ CH₂ CHF--, --CH₂ CH₂ CH₂ CH₂ CH₂ CF₂ --, --CH₂ CH₂ CH₂CF₂ CH₂ CH₂ CH₂ --, and --CH₂ CH₂ CH₂ CH₂ CH₂ CH₂ CH₂ CF₂ --.

PGE₂, PGF₂.sub.α, PGF₂.sub.β, PGA₂, and PGB₂, and their esters andpharmacologically acceptable salts, are extremely potent in causingvarious biological responses. For that reason, these compounds areuseful for pharmacological purposes. See, for example, Bergstrom et al.,Pharmacol. Rev. 20, 1 (1968), and references cited therein. A few ofthose biological responses are systemic arterial blood pressure loweringin the case of PGE₂, PGF₂.sub.β, and PGA₂ as measured, for example, inanesthetized (pentobarbital sodium) pentolinium-treated rats withindwelling aortic and right heart cannulas; pressor activity, similarlymeasured, for PGF₂.sub.α ; stimulation of smooth muscle as shown, forexample, by tests on strips of guinea pig ileum, rabbit duodenum, orgerbil colon; potentiation of other smooth muscle stimulants;antilipolytic activity as shown by antogonism of epinephrine-inducedmobilization of free fatty acids or inhibition of the spontaneousrelease of glycerol from isolated rat fat pads; inhibition of gastricsecretion in the case of PGE₂ and PGA₂ as shown in dogs with secretionstimulated by food or histamine infusion; activity on the centralnervous system; decrease of blood platelet adhesiveness as shown byplatelet-to-glass adhesiveness, and inhibition of blood plateletaggregation and thrombus formation induced by various physical stimuli,e.g., arterial injury, and various biochemical stimuli, e.g., ADP, ATP,serotonin, thrombin, and collagen; and in the case of PGE₂ and PGB₂,stimulation of epidermal proliferation and keratinization as shown whenapplied in culture to embryonic chick and rat skin segments.

Because of these biological responses, these known prostaglandins areuseful to study, prevent, control, or alleviate a wide variety ofdiseases and undesirable physiological conditions in birds and mammals,including humans, useful domestic animals, pets, and zoologicalspecimens, and in laboratory animals, for example, mice, rats, rabbits,and monkeys.

For example, these compounds, and especially PGE₂, are useful inmammals, including man, as nasal decongestants. For this purpose, thecompounds are used in a dose range of about 10 μg. to about 10 mg. perml. of a pharmacologically suitable liquid vehicle or as an aerosolspray, both for topical application.

PGE₂ and PGA₂ are useful in mammals, including man and certain usefulanimals, e.g., dogs and pigs, to reduce and control excessive gastricsecretion, thereby reducing or avoiding gastrointestinal ulcerformation, and accelerating the healing of such uclers already presentin the gastrointestinal tract. For this purpose, the compounds areinjected or infused intravenously, subcutaneously, or intramuscularly inan infusion dose range about 0.1 μg. to about 500 μg. per kg. of bodyweight per minute, or in a total daily dose by injection or infusion inthe range about 0.1 to about 20 mg. per kg. of body weight per day, theexact dose depending on the age, weight, and condition of the patient oranimal, and on the frequency and route of administration.

PGE₂, PGA₂, PGF₂.sub.α, and PGF₂.sub.β are useful whenever it is desiredto inhibit platelet aggregation, to reduce the adhesive character ofplatelets, and to remove or prevent the formation of thrombi in mammals,including man, rabbits, and rats. For example, these compounds areuseful in the treatment and prevention of myocardial infarcts, to treatand prevent post-operative thrombosis, to promote patency of vasculargrafts following surgery, and to treat conditions such asatherosclerosis, arteriosclerosis, blood clotting defects due tolipemia, and other clinical conditions in which the underlying etiologyis associated with lipid imbalance or hyperlipidemia. For thesepurposes, these compounds are administered systemically, e.g.,intravenously, subcutaneously, intramuscularly, and in the form ofsterile implants for prolonged action. For rapid response, especially inemergency situations, the intravenous route of administration ispreferred. Doses in the range about 0.004 to about 20 mg. per kg. ofbody weight per day are used, the exact dose depending on the age,weight, and condition of the patient or animal, and on the frequency androute of administration.

PGE₂, PGA₂, PGF₂.sub.α, and PGF₂.sub.β are especially useful asadditives to blood, blood products, blood substitutes, and other fluidswhich are used in artificial extracorporeal circulation and perfusion ofisolated body portions, e.g., limbs and organs, whether attached to theoriginal body, detached and being preserved or prepared for transplant,or attached to a new body. During these circulations and perfusions,aggregated platelets tend to block the blood vessels and portions of thecirculation apparatus. This blocking is avoided by the presence of thesecompounds. For this purpose, the compound is added gradually or insingle or multiple portions to the circulating blood, to the blood ofthe donor animal, to the perfused body portion, attached or detached, tothe recipient, or to two or all of those at a total steady state dose ofabout 0.001 to 10 mg. per liter of circulating fluid. It is especiallyuseful to use these compounds in laboratory animals, e.g., cats, dogs,rabbits, monkeys, and rats, for these purposes in order to develop newmethods and techniques for organ and limb transplants.

PGE₂ is extremely potent in causing stimulation of smooth muscle, and isalso highly active in potentiating other known smooth musclestimulators, for example, oxytocic agents, e.g., oxytocin, and thevarious ergot alkaloids including derivatives and analogs thereof.Therefore PGE₂ is useful in place of or in combination with less thanusual amounts of these known smooth muscle stimulators, for example, torelieve the symptoms of paralytic ileus, to control or prevent atonicuterine bleeding after abortion or delivery, to aid in expulsion of theplacenta, and during the puerperium. For these purposes, PGE₂ isadministered by intravenous infusion immediately after abortion ordelivery at a dose in the range about 0.01 to about 50 μg. per kg. ofbody weight per minute until the desired effect is obtained. Subsequentdoses are given by intravenous, subcutaneous, or intramuscular injectionor infusion during puerperium in the range 0.01 to 2 mg. per kg. of bodyweight per day, the exact dose depending on the age, weight, andcondition of the patient or animal.

PGE₂, PGA₂, and PGF₂.sub.β are useful as hypotensive agents to reduceblood pressure in mammals, including man. For this purpose, thecompounds are administered by intravenous infusion at the rate about0.01 to about 50 μg. per kg. of body weight per minute or in single ormultiple doses of about 25 to 500 μg. per kg. of body weight total perday.

PGF₂.sub.α, PGF₂.sub.β, and PGE₂ are useful for controlling thereproductive cycle in ovulating female mammals, including humans andanimals such as monkeys, rats, rabbits, dogs, cattle, and the like. Forthat purpose, PGF₂.sub.α is administered systemically at a dose level inthe range 0.01 mg. to about 20 mg. per kg. of body weight of the femalemammal, advantageously during a span of time starting approximately atthe time of ovulation and ending approximately at the time of menses orjust prior to menses.

As mentioned above, PGE₂ is a potent antagonist of epinephrine-inducedmobilization of free fatty acids. For this reason, this compound isuseful in experimental medicine for both in vitro and in vivo studies inmammals, including man, rabbits, and rats, intended to lead to theunderstanding, prevention, symptom alleviation, and cure of diseasesinvolving abnormal lipid mobilization and high free fatty acid levels,e.g., diabetes mellitus, vascular diseases, and hyperthyroidism.

PGE₂ and PGB₂ promote and accelerate the growth of epidermal cells andkeratin in animals, including humans, useful domestic animals, pets,zoological specimens, and laboratory animals. For that reason, thesecompounds are useful to promote and accelerate healing of skin which hasbeen damaged, for example, by burns, wounds, and abrasions, and aftersurgery. These compounds are also useful to promote and accelerateadherence and growth of skin autografts, especially small, deep (Davis)grafts which are intended to cover skinless areas by subsequent outwardgrowth rather than initially, and to retard rejection of homografts.

For these purposes, these compounds are preferably administeredtopically at or near the site where cell growth and keratin formation isdesired, advantageously as an aerosol liquid or micronized powder spray,as an isotonic aqueous solution in the case of wet dressings, or as alotion, cream, or ointment in combination with the usualpharmaceutically acceptable diluents. In some instances, for example,when there is substantial fluid loss as in the case of extensive burnsor skin loss due to other causes, systemic administration isadvantageous, for example, by intravenous injection or infusion,separate or in combination with the usual infusions of blood, plasma, orsubstitutes thereof. Alternative routes of administration aresubcutaneous or intramuscular near the site, oral, sublingual, buccal,rectal, or vaginal. The exact dose depends on such factors as the routeof administration, and the age, weight, and condition of the subject. Toillustrate, a wet dressing for topical application to second and/orthird degree burns of skin area 5 to 25 square centimeters wouldadvantageously involve use of an isotonic aqueous solution containing 1to 500 μg./ml. of PGB₂ or several times that concentration of PGE₂.Especially for topical use, these prostaglandins are useful incombination with antibiotics, for example, gentamycin, neomycin,polymyxin B, bacitracin, spectinomycin, and oxytetracycline, with otherantibacterials, for example, mafenide hydrochloride, sulfadiazine,furazolium chloride, and nitrofurazone, and with corticoid steroids, forexample, hydrocortisone, prednisolone, methylprednisolone, andfluprednisolone, each of those being used in the combination at theusual concentration suitable for its use alone.

Racemic PGE₂, racemic PGF₂, racemic PGF₂.sub.β, racemic PGA₂, andracemic PGB₂ each are useful for the purposes described above for theoptically active compounds, but there racemic compounds offer theenormous advantage of being available in unlimited quantities at muchlower cost. Moreover, these racemic compounds are easier to purify sincethey are produced by chemical reactions rather than by extraction frombiological materials or enzymatic reaction mixtures.

The other racemic compounds encompassed by formulas VIII, IX, X, and XI,and also the acetylenic compounds 5,6-dehydro-PGE₂,5,6-dehydro-PGF₂.sub.α, 5,6-dehydro-PGF₂.sub.β, 5,6-dehydro-PGA₂, and5,6-dehydro-PGB₂ and the other compounds encompassed by formulas XII,XIII, XIV, and XV each cause the biological responses described abovefor the corresponding knonw prostaglandins, and eachof these novelracemic compounds is accordingly useful for the above-describedcorresponding purposes, and is used for those purposes in the samemanner as described above.

The known optically active prostaglandins PGE₂, PGF₂.sub.α, PGF₂.sub.β,PGA₂, and PGB₂ are all potent in causing multiple biological responseseven at low doses. For example, PGE₂ is extremely potent in causingvaso-depression and smooth muscle stimulation, and also is potent as anantilipolytic agent. In striking contrast, the analogs of formulas VIII,IX, X, and XI, and also the acetylenic formula XII, XIII, XIV, and XVare substantially more specific with regard to potency in causingprostaglandin-like biological responses. Therefore, each of these novelprostaglandin analogs is surprisingly and unexpectedly more useful thanone of the corresponding above-mentioned prostaglandins for at least oneof the pharmacological purposes indicated above for the latter. Use ofthe novel analog for that purpose results in smaller undesired sideeffects than when the known prostaglandin is used for the same purpose.

To obtain the optimum combination of biological response specificity andpotency, certain compounds within the scope of formulas VIII and IX arepreferred. As discussed above, those formulas represent in PGE₂ -typecompounds and the PGF₂.sub.α -type compounds, respectively. Referring toformulas VIII and IX, when --CH₂ --CH=CH--A--COOR₁ is attached in alphaconfiguration and, in the case of formula IX, when the ring hydroxy isalso attached in alpha configuration, stereochemistry typical of theknown optically active PGE₂ and PGF₂.sub.α, it is preferred thatterminal alkyl group R₂ not be pentyl at the same time that alkylenegroup A is straight chain and unsubstituted. In other words, accordingto this invention, preferred formula VIII and IX compounds wherein --CH₂--CH=CH--A--COOR₁ and ring hydroxy are alpha are those wherein R₂ isbranched chain or fluoro-substituted alkyl when A is straight chainunsubstituted alkylene, those wherein A is branched chain orfluoro-substituted when R₂ is pentyl, and those wherein R₂ is alkylother than pentyl, i.e., alkyl to one to 4 carbon atoms, inclusive, oralkyl of 6 to 8 carbon atoms, inclusive. These preferred compoundsexhibit superior biological response specificity and/or potency. Forreasons not completely understood, fluoro-substitution or branching ofat least one of A and R₂ in these particular groups of formula VIII andformula IX compounds, increases biological response specificity and/orpotency. This is especially true in the case of A when R₂ is pentyl.

Certain compounds within the scope of formulas VIII to XV are especiallyuseful for one or more of the purposes stated above for PGE₂,PGF₂.sub.α, PGF₂.sub.β, PGA₂, and PGB₂, because they have asubstantially longer duration of activity than other compounds withinthe generic formulas, including PGE₂, PGF₂.sub.α, PGF₂.sub.β, PGA₂, andPGB₂, and because they can be administered orally, sublingually,intravaginally, bucally, or rectally, rather than by the usualintravenous, intramuscular, or subcutaneous injection or infusion asindicated above for the uses of these known prostaglandins and the othercompounds encompassed by formulas VIII to XV. These qualities areadvantageous because they facilitate maintaining uniform levels of thesecompounds in the body with fewer, shorter, or smaller doses, and makepossible self-administration by the patient.

With reference to formulas VIII to XV, these special compounds includethose wherein A is --(CH₂)_(b) --Z--, wherein b is zero, one, 2, or 3,and Z is ethylene substituted by one or 2 fluoro, methyl, or ethyl, orby one alkyl of 3 or 4 carbon atoms. These special compounds alsoinclude those wherein R₂ is --(CH₂)_(d) --X, wherein d is zero, one, 2,3, or 4, and X is isobutyl, tert-butyl, 3,3-difluorobutyl,4,4-difluorobutyl, or 4,4,4-trifluorobutyl. These special compounds alsoinclude those wherein A is --(CH₂)_(b) --Z-- as above defined, and R₂ is--(CH₂)_(d) --X as above defined. Especially preferred among thesespecial compounds are those wherein R₃ and R₄ are both hydrogen.

In the case of Z, the divalent ethylene group, --CH₂ --CH₂ --, issubstituted on either or both carbon atoms, i.e., alpha and/or beta tothe carboxylate function. For example, Z is --CH₂ --CHF--, --CHF--CH₂--, --CH₂ --CF₂ --, --CF₂ --CH₂ --, --CHF--CHF--, --CH₂ --CH(CH₃)--,--CH(CH₃)--CH₂ --, --CH₂ --C(CH₃)₂ --, --C(CH₃)₂ --CH₂ --,--CH(CH₃)--CH(CH₃)--, and similarly for ethyl, and for one fluoro andone methyl, one fluoro and one ethyl, and one methyl and one ethyl. Z isalternatively ethylene substituted on either carbon atom with propyl,isopropyl, butyl, isobutyl, sec-butyl, or tert-butyl.

Although all of the special compounds just described have the specialadvantages of long duration and oral, sublingual intravaginal, andrectal routes of administration, there is a still more limited group ofcompounds encompassed by these formulas which have these qualities in aparticularly high degree. Those are the compounds wherein A is --CH₂--Z--, i.e., wherein b in --(CH₂)_(b) --Z--is one, especially when Z isethylene with one fluoro or methyl, with 2 fluoro or 2 methyl on thesame carbon atom, or with butyl, isobutyl, sec-butyl, or tert-butyl onthe carbon atoms alpha (adjacent) to the carboxylate function, thecompounds wherein R₂ is --CH₂ CH₂ CH₂ C(CH₃)₃, --CH₂ CH₂ CH₂ CH(CH₃)₂,--CH₂ CH₂ CH₂ CH₂ CF₃, --CH₂ CH₂ CH₂ CH₂ CHF₂, or --CH₂ CH₂ CH₂ CF₂ CH₃,and the compounds wherein both A and R₂ are both defined in these morelimited ways.

Racemic PGE₂, racemic PGF₂.sub.α, racemic PGF₂.sub.β, racemic PGA₂,racemic PGB₂, the corresponding 5,6-dehydro, and the other compoundsencompassed by formulas VIII to XV, including the special classes ofcompounds described above are used for the purposes described above inthe free acid form, in ester form, or in pharmacologically acceptablesalt form. When the ester form is used, the ester is any of those withinthe above definition of R₁. However, it is preferred that the ester bealkyl of one to four carbon atoms, inclusive. Of those alkyl, methyl andethyl are especially preferred for optimum absorption of the compound bythe body or experimental animal system.

Pharmacologically acceptable salts of these formula VII to XV compoundsuseful for the purposes described above are those with pharmacologicallyacceptable metal cations, ammonium, amine cations, or quaternaryammonium cations.

Especially preferred metal cations are those derived from the alkalimetals, e.g., lithium, sodium, and potassium, and from the alkalineearth metals, e.g., magnesium and calcium, although cationic forms ofother metals, e.g., aluminum, zinc, and iron, are within the scope ofthis invention.

Pharmacologically acceptable amine cations are those derived fromprimary, secondary, or tertiary amines. Examples of suitable amines aremethylamine, dimethylamine, trimethylamine, ethylamine, dibutylamine,triisopropylamine, N-methylhexylamine, decylamine, dodecylamine,allylamine, crotylamine, cyclopentylamine, dicyclohexylamine,benzylamine, dibenzylamine, α-phenylethylamine, β-phenylethylamine,ethylenediamine, diethylenetriamine, and the like aliphatic,cycloaliphatic, and araliphatic amines containing up to and includingabout 18 carbon atoms, as well as heterocyclic amines, e.g., piperidine,morpholine, pyrrolidine, piperazine, and lower-alkyl derivativesthereof, e.g., 1-methylpiperidine, 4-ethylmorpholine,1-isopropylpyrrolidine, 2-methylpyrrolidine, 1,4-dimethylpiperazine,2-methylpiperidine, and the like, as well as amines containingwater-solubilizing or hydrophilic groups, e.g., mono-, di-, andtriethanolamine, ethyldiethanolamine, N-butylethanolamine,2-amino-1-butanol, 2-amino-2-ethyl-1,3-propanediol,2-amino-2-methyl-1-propanol, tris(hydroxymethyl)aminomethane,N-phenylethanolamine, N-(p-tert-amylphenyl)diethanolamine, galactamine,N-methylglucamine, N-methylglucosamine, ephedrine, phenylephrine,epinephrine, procaine, and the like.

Examples of suitable pharmacologically acceptable quaternary ammoniumcations are tetramethylammonium, tetraethylammonium,benzyltrimethylammonium, phenyltriethylammonium, and the like.

As discussed above, the compounds of formulas VIII to XV areadministered in various ways for various purposes, e.g., intravenously,intramuscularly, subcutaneously, orally, intravaginally, rectally,buccally, sublingually, topically, and in the form of sterile implantsfor prolonged action.

For intravenous injection or infusion, sterile aqueous isotonicsolutions are preferred. For that purpose, it is preferred because ofincreased water solubility that R₁ in the formula VIII to XV compound behydrogen or a pharmacologically acceptable cation. For subcutaneous orintramuscular injection, sterile solutions or suspensions of the acid,salt, or ester form in aqueous or non-aqueous media are used. Tablets,capsules, and liquid preparations such as syrups, elixers, and simplesolutions, with the usual pharmaceutical carriers are used for oral orsublingual administration. For rectal or vaginal administration,suppositories prepared as known in the art are used. For tissueimplants, a sterile tablet or silicone rubber capsule or other objectcontaining or impregnated with the substance is used.

Racemic PGE₂, racemic PGF₂.sub.α, racemic PGF₂.sub.β , racemic PGA₂,racemic PGB₂, the corresponding 5,6-dehydroprostaglandins, and the othercompounds encompassed by formulas VIII to XV are produced by thereactions and procedures described hereinafter.

Racemic PGF₂.sub.α, racemic PGF₂.sub.β, 5,6-dehydro-PGF₂.sub.α,5,6-dehydro-PGF₂.sub.β, and the other PGF₂ -type compounds encompassedby formulas IX and XIII are prepared by carbonyl reduction of thecorresponding PGE₂ -type compounds encompassed by formulas VIII and XII.For example, carbonyl reduction of racemic PGE₂ gives a mixture ofracemic PGF₂.sub.α and racemic PGF₂.sub.β.

These ring carbonyl reductions are carried out by methods known in theart for ring carbonyl reductions of known prostanoic acid derivatives.See, for example, Bergstrom et al., Arkiv Kemi, 19, 563 (1963), and ActaChem. Scand. 16, 969 (1962), and British Specification No. 1,097,533.Any reducing agent is used which does not react with carbon-carbondouble bonds or ester groups. Preferred reagents are aluminum(tri-tert-butoxy) hydride and the metal borohydrides, especially sodium,potassium and zinc borohydrides. The mixtures of alpha and beta hydroxyreduction products are separated into the individual alpha and betaisomers by methods known in the art for the separation of analogouspairs of known isomeric prostanoic acid derivatives. See, for example,Bergstrom et al., cited above, Granstrom et al., J. Biol. Chem. 240, 457(1965), and Green et al., J. Lipid Research, 5, 117 (1964). Especiallypreferred as separation methods are partition chromatographicprocedures, both normal and reversed phase, preparative thin layerchromatography, and countercurrent distribution procedures.

Racemic PGA₂, 5,6-dehydro-PGA₂, and the other PGA₂ -type compoundsencompassed by formulas X and XIV are prepared by acidic dehydration ofthe corresponding PGE₂ -type compounds encompassed by formulas VIII andXII. For example, acidic dehydration of racemic PGE₂ gives racemic PGA₂.

These acidic dehydrations are carried out by methods known in the artfor acidic dehydrations of known prostanoic acid derivatives. See, forexample, Pike et al., proc. Nobel Symposium II, Stockholm (1966);Interscience Publishing Co., New York, pp. 162-163 (1967), and BritishSpecification 1,097,533. Alkanoic acids of 2 to 6 carbon atoms,inclusive, especially acetic acid, are preferred acids for this acidicdehydration.

Racemic PGB₂, 5,6-dehydro-PGB₂, and the other compounds encompassed byformulas XI and XV are prepared by basic dehydration of thecorresponding PGE₂ -type compounds encompassed by formulas VIII and XII,or by contacting the corresponding PGA₂ -type compounds encompassed byformulas X and XIV with base. For example, both racemic PGE₂ and racemicPGA₂ give racemic PGB₂ on treatment with base. Presumably the base firstcauses dehydration of the PGE₂ to PGA₂, and then causes the ring doublebond of PGA₂ to migrate to a new position.

These basic dehydrations and double bond migrations are carried out bymethods known in the art for similar reactions of known prostanoic acidderivatives. See, for example, Bergstrom et al., J. Biol. Chem. 238,3555 (1963). The base is any whose aqueous solution has pH greater than10. Preferred bases are the alkali metal hydroxides. A mixture of waterand sufficient of a water-miscible alkanol to give a homogeneousreaction mixture is suitable as a reaction medium. The PGE₂ -type orPGA₂ -type compound is maintained in such a reaction medium until nofurther PGB₂ -type compound is formed, as shown by the characteristicultraviolet light absorption near 278 mμ for the PGB₂ -type compound.

These various transformations of the PGE₂ -type compounds of formulasVIII and XII to the PGF₂ -type. PGA₂ -type, and PGB₂ -type compounds areshown in Chart A, wherein R₁, R₂, R₃, R₄, A, and ˜ are as defined above,and V is cis--CH=CH-- or --C.tbd.C-- .

Racemic PGE₂, 5,6-dehydro-PGE₂, and the other PGE₂ -type compoundsencompassed by formulas VIII ad XII are prepared by the multi-stepprocess outlined in Charts B, C, D, E, and F. ##SPC16## ##SPC17####SPC18## ##SPC19## ##SPC20## ##SPC21##

In those Charts, R₁, R₂, R₃, R₄, A, and ˜ attached to the cyclopentanering are as defined above. V is cis--CH=CH-- or --C.tbd.C--. R₁₂ and R₁₃are alkyl of one to 4 carbon atoms, inclusive. R₁₄ is the same as R₁except that R₁₄ does not include hydrogen. R₁₅ is alkyl of one to 5carbon atoms, inclusive. The symbol ˜ attached to the cyclopropane ringindicates exo or endo configuration for the moiety so attached.

The bicyclo-ketone of formula XVI in Chart B is the initial reactant inthese multi-step processes. That ketone exists in four isomeric forms,exo and endo with respect to the attachment of the --CR₄ =CR₂ R₃ moiety,and cis and trans with respect to the double bond in that same moiety.Each of those isomers separately or various mixtures thereof are used asreactants according to this invention to produce substantially the samefinal PGE₂ type or 5,6-dehydro-PGE₂ -type product mixture.

In exo configuration, the formula XVI keto is known to the art. SeeBelgian patent No. 702,477; reprinted in Farmdoc CompleteSpecifications, Book 714, No. 30,905, page 313, March 12, 1968.

In that Belgian patent, the reaction sequence leading to exo ketone XVIis as follows: The hydroxy of 3-cyclopentenol is protected, for example,with a tetrahydropyranyl group. Then a diazoacetic acid ester is addedto the double bond to give an exo-endo mixture of a bicyclo[3.1.0]hexanesubstituted at 3 with the protected hydroxy and at 6 with an esterifiedcarboxyl. The exo-endo mixture is treated with a base to isomerize theendo isomer in the mixture to more of the exo isomer. Next, thecarboxylate ester group at 6 is transformed to an aldehyde group orketone group, --CHO or ##STR7## wherein R₄ is as defined above. Then,said aldehyde group or said keto group is transformed by the Wittigreaction to a moiety of the formula --CR₄ =CR₂ R₃ which is in exoconfiguration relative to the bicyclo ring structure, and is the same asshown in formula XVI. Next, the protective group is removed toregenerate the 3-hydroxy which is then oxidized, for example, by theJones reagent, to give said exo ketone XVI.

Separation of the cis-exo and trans-exo isomers of XVI is described insaid Belgian patent. However, as mentioned above, that separation isusually not necessary since the cis-trans mixture is useful as areactant in the next process step.

The process described in said Belgian patent No. 702,477 for producingthe exo form of bicyclo-ketone XVI uses as an intermediate, the exo formof a bicyclo[3.1.0]hexane substituted at 3 with a protected hydroxy,e.g., tetrahydropyranyloxy and at 6 with an esterified carboxyl. Whenthe corresponding endo compound is substituted for that exointermediate, the Belgian patent process leads to the endo form ofbicyclo-ketone XVI. That endo intermediate used in the Belgian patentprocess has the formula: ##SPC22##

Compound XL is prepared by reactingendo-bicyclo[3.1.0]hex-2-ene-6-carboxylic acid methyl ester withdiborane in a mixture of tetrahydrofuran and diethyl ether, a reactiongenerally known in the art, to give endo-bicyclo[3.1.0]hexan-3-ol-6-carboxylic acid methyl ester which is then reacted with dihydropyranin the presence of a catalytic amount of POCl.sub. 3 to give the desiredcompound. This is then used as described in said Belgian patent toproduce the endo form of bicyclo-ketone XVI.

As for exo XVI, this process produces a mixture of endo-cis andendo-trans. These are separated as described for the separation ofexo-cis and exo-trans XVI, but this separation is usually not necessarysince, as mentioned above, the cis-trans mixture is useful as a reactantin the next process step.

In the process of said Belgian patent No. 702,477, certain organichalides, e.g., chlorides and bromides, are necessary to prepare theWittig reagents used to generate the generic moiety --CR₄ =CR₂ R₃ ofbicyclo-ketone XVI. These organic chlorides and bromides ##STR8## and##STR9## are known in the art or can be prepared by methods known in theart.

To illustrate the availability of these organic chlorides and bromides,consider the above-described special compounds of formula VIII, forexample, wherein R₂ is --(CH₂)_(d) --X; wherein d is zero, one, 2, 3, or4, and X is isobutyl, tert-butyl, 3,3-difluorobutyl, 4,4-difluorobutyl,or 4,4,4-trifluorobutyl. The halides are advantageously prepared byreacting the corresponding primary alcohol, R₂ CH₂ OH, or secondaryalcohol ##STR10## wherein R₃ is as defined above, with PCl₃, PBr₃, orany of the other halogenating agents known to the art to be useful forthis purpose.

In the case of X being isobutyl or tert-butyl, some of the necessarylower molecular weight primary alcohols, e.g., (CH₃)₂ CHCH₂ CH₂ OH and(CH₃)₃ CCH₂ OH, are known. The remainder of the alcohols are prepared byreacting the bromides corresponding to those known alcohols with sodiumcyanide, hydrolyzing the resulting nitriles to the correspondingcarboxylic acids, and then reducing those acids to the correspondingprimary alcohols with lithium aluminum hydride, thus extending thecarbon chain one carbon atom at a time until all primary alcohols areprepared. The corresponding secondary alcohols, ##STR11## are preparedby transforming the --COOH of the correspond-carboxylic acid, all ofwhich are known or prepared as just described, to ##STR12## by knownprocedures, for example, R₂ COCl + (R₃)₂ Cd, the resulting ketone thenbeing reduced to the secondary alcohol with sodium borohydride.

In the case of X being 3,3-difluorobutyl, the necessary alcohols areprepared from ketocarboxylic acids of the formula, CH₃ --CO--(CH₂)_(n)--COOH, wherein n is 2, 3, 4, 5, or 6. All of those acids are known. Themethyl esters are prepared and reacted with sulfur tetrafluoride toproduce the corresponding CH₃ --CF₂ --(CH₂)_(n) --COOCH₃ compounds,which are then reduced with lithium aluminum hydride to CH₃ --CF₂--(CH₂)_(n) --CH₂ OH, or transformed as described above to ##STR13##These alcohols are then transformed to the bromide or chloride byreaction with PBr₃ or PCl₃.

In the case of X being 4,4-difluorobutyl, the initial reactants are theknown dicarboxylic acids, HOOC--(CH₂)_(f) --COOH, wherein f is 3, 4, 5,6, or 7. These dicarboxylic acids are esterified to CH₃ OOC--(CH₂)_(f)--COOCH₃ and then half saponified, for example with barium hydroxide, togive HOOC--(CH₂)_(f) --COOCH₃. The free carboxyl group is transformedfirst to the acid chloride with thionyl chloride and then to an aldehydeby the Rosenmund reduction. Reaction of the aldehyde with sulfurtetrafluoride then gives CHF₂ --(CH₂)_(f) --COOCH₃ which by successivetreatment with lithium aluminum hydride and PBr₃ or PCl₃ gives thenecessary bromides or chlorides, CHF₂ --(CH₂)_(f) --CH₂ Br or CHF₂--(CH₂)_(f) --CH₂ Cl. Those formulas can be rewritten as CHF₂ CH₂ CH₂CH₂ (CH₂)_(d) --CH₂ Br or CHF₂ CH₂ CH₂ CH₂ (CH₂)_(d) --CH.sub. 2 Cl.Corresponding secondary alcohols are prepared as described above.

In the case of X being 4,4,4-trifluorobutyl, aldehydes of the formulaCH₃ OOC--(CH₂)_(f) --CHO are prepared as described above. Reduction ofthe aldehyde with sodium borohydride gives the alcohol CH₃OOC--(CH₂)_(f) --CH₂ OH. Reaction with PBr₃ or PCl₃ then gives CH₃OOC--(CH₂)_(f) --CH₂ --X, wherein X is Br or Cl. Saponification of thatester gives the carboxylic acid which by reaction with sulfurtetrafluoride gives the necessary CF₃ --(CH₂)_(f) --CH₂ --Br or CF₃--(CH₂)_(f) --CH₂ --Cl. Corresponding secondary alcohols are prepared bytransforming CH₃ OOC--(CH₂)_(f) --CHO to CH₃ OOC--(CH₂)_(f) --COCH₃ byknown methods, and then proceeding with that ketone as described abovefor the aldehyde.

For the above reactions of SF₄, see U.S. Pat. No. 3,211,723 and J. Org.Chem. 27, 3164 (1962).

The transformation of bicyclo-ketone-olefin XVI to glycol XVII (chart B)is carried out by reacting olefin XVI with a hydroxylation reagent.Hydroxylation reagents and procedures for this purpose are known in theart. See, for example, Gunstone, Advances in Organic Chemistry, Vol. 1,pp. 103-147, Interscience Publishers, New York, N.Y. (1960). Variousisomeric glycols are obtained depending on whether olefin XVII is cis ortrans and endo or exo, and on whether a cis or a trans hydroxylationreagent is used. Thus endo-cis olefin XVI gives a mixture of twoisomeric erythro glycols of formula XVII with a cis hydroxylation agent,e.g., osmium tetroxide. Similarly, the endo-trans olefin XVI gives asimilar mixture of the same two erythro glycols with a transhydroxylation agent, e.g., hydrogen peroxide. The endo-cis olefins andthe endo-trans olefins XVI give similar mixtures of two threo isomerswith cis and trans hydroxylation reagents, respectively. These variousglycol mixtures are separated into individual isomers by silica gelchromatography. However, this separation is usually not necessary, sinceeach isomeric erythro glycol and each isomeric threo glycol is useful asan intermediate according to this invention and the processes outlinedin Charts B, C, E, and F to produce final products of formulas VIII andXII, and then, according to Chart A, to produce the other final productsof this invention. Thus the various isomeric glycol mixtures encompassedby formula XVII produced from the various isomeric olefins encompassedby formula XVI are all useful for these same purposes.

The transformation of glycol XVII to the cyclic ketal of formula XVIII(Chart B) is carried out by reacting said glycol with a dialkyl ketoneof the formula ##STR14## wherein R₁₂ and R₁₃ are alkyl of one to 4carbon atoms, inclusive, in the presence of an acid catalyst, forexample potassium bisulfate or 70% aqueous perchloric acid. A largeexcess of the ketone and the absence of water is desirable for thisreaction. Examples of suitable dialkyl ketones are acetone, methyl ethylketone, diethyl ketone, methyl propyl ketone, and the like. Acetone ispreferred as a reactant in this process.

The transformation of cyclic ketal XVIII to cyclic ketal XIX is carriedout by alkylating ketal XVIII with an acetylenic alkylating agent offormula XX (Chart C), wherein A is as defined above, and Hal ischlorine, bromine, or iodine.

Any of the alkylation procedures known in the art to be useful foralkylating cyclic ketones with alkyl halides, especially haloalkanoicesters, are used for the transformation of XVIII to XIX. See, forexample, the above mentioned Belgian patent No. 702,477 for proceduresuseful here and used there to carry out similar alkylations.

For this alkylation, it is preferred that Hal be bromo. Any of the usualalkylation bases, e.g., alkali metal alkoxides, alkali metal amides, andalkali metal hydrides, are useful for this alkylation. Alkali metalalkoxides are preferred, especially tert-alkoxides. Sodium and potassiumare preferred alkali metals. Especially preferred is potassiumtert-butoxide. Preferred diluents for this alkylation aretetrahydrofuran and 1,2-dimethoxyethane. Otherwise, procedures forproducing and isolating the desired formula XIX compound are within theskill of the art.

This alkylation procedure produces a mixture of alpha and betaalkylation products, i.e., a mixture of formula XIX products whereinpart has the ##SPC23##

moiety attached in alpha configuration and wherein part has that moietyattached in beta configuration. When about one equivalent of base perequivalent of formula XVIII ketone is used, the alpha configurationusually predominates. Use of an excess of base and longer reaction timesusually result in production of larger amounts of beta products. Thesealpha-beta isomer mixtures are separated at this stage or at anysubsequent stage in the multi-step processes shown in Charts D, E, andF. Silica gel chromatography is preferred for this separation.

The alkylating agent of formula XX is prepared by the series ofreactions shown in Chart C. The initial reactants, Br--A--CH₂ OH, areomega bromoalcohols which are known in the art or can be prepared bymethods known in the art. For example, when A in the final product is tobe trimethylene as it is in racemic PGE₂ and 5,6-dehydro-PGE₂, thenecessary 4-bromobutanol is prepared by reacting tetrahydrofuran withhydrogen bromide.

To illustrate the availability of the other bromoglycols of formula XXIV(Chart C), consider the above-described special compounds of formulaVIII, wherein A is --(CH₂)_(b) --Z--, wherein b is zero, one, 2, or 3,and Z is ethylene substituted by one or 2 fluoro, methyl, or ethyl, orby one alkyl of 3 or 4 carbon atoms. These omega-bromoalcohols,Br--(CH₂)_(b) --Z--CH₂ OH, are prepared by starting with the appropriatesuccinic acid, HOOC--Z--COOH, all of which are known or easilyaccessible by known methods. These succinic acids are transformed to thecorresponding anhydrides by known procedures. Each anhydride is thenreacted with an alkanol, for example, methanol, to give thecorresponding succinic acid half ester, e.g., HOOC--Z--COOCH₃. When Z isunsymmetrical, e.g., substituted with one fluoro, a mixture of isomerichalf esters is obtained, HOOC--Z--COOCH₃ and CH₃ --OOC--Z--COOH, whichis separated to give the desired isomer.

When it is desired that b in Br--(CH₂)_(b) --Z--CH₂ OH be zero, thesuccinic acid half ester is subjected to the Hunsdiecker reaction,thereby producing BR--Z--COOCH₃, which is reduced by lithium aluminumhydride to BR--Z--CH₂ OH. When b is to be one, the carboxyl group of thesuccinic acid half ester is changed to acid chloride with thionylchloride, to aldehyde by the Rosenmund reduction, to alcohol with sodiumborohydride, and to --CH₂ Br with PBr₃, giving Br--CH₂ --Z--COOCH₃,which is then reduced to Br--CH₂ --Z--CH₂ OH with lithium aluminumhydride. When b is to be 2 or 3, the succinic acid half ester issubjected once or twice to the Arndt-Eistert reaction to produceHOOC--CH₂ --Z--COOCH₃ or HOOC--CH₂ CH₂ --Z--COOCH₃, which is thensubjected to the same series of reactions given above to give Br--CH₂CH₂ --Z--CH₂ OH or Br--CH₂ CH₂ CH₂ --Z--CH₂ OH.

Referring again to Chart C, the several process steps, XXIV to XXIII,XXIII to XXII, XXII to XXI, and XXI to XX are exemplified hereinafter inthe case wherein A is trimethylene. Those procedures are used when A isother than trimethylene and within the scope of A as defined above.

The transformation of alkylation product XIX to primary alcohol XXV(Chart B) is carried out by treating the tetrahydropyranyl ether XIXwith any strong acid under such conditions that the cyclic acetal groupremains intact. Hydrolysis of tetrahydropyranyl ethers under suchconditions is well known to those skilled in the art. Oxalic acid isespecially preferred for this acid hydrolysis of XIX to XXV.

The oxidation of primary alcohol XXV to carboxylic acid XXVI (Chart B)is carried out by oxidizing XXV with any oxidizing agent which will notalso attack the acetylenic linkage in XXV. An especially useful reagentfor this purpose is the Jones reagent, i.e., acidic chromic acid. See J.Chem. Soc. 39 (1946). Acetone is a suitable diluent for this purpose,and a slight excess of oxidant and temperatures at least as low as about0° C., preferably about -10° to about -20° C. should be used. Theoxidation proceeds rapidly and is usually complete in about 5 to about30 minutes. Excess oxidant is destroyed, for example, by addition of alower alkanol, advantageously isopropyl alcohol, and the aldehyde isisolated by conventional methods, for example, by extraction with asuitable solvent, e.g., diethyl ether. Other oxidizing agents can alsobe used. Examples are mixtures of chromium trioxide and pyridine ormixtures of dicyclohexylcarbodiimide and dimethyl sulfoxide. See, forexample, J. Am. Chem. Soc. 87, 5661 (1965).

As shown on Charts B, D, and E, carboxylic acid XXVI leads to PG₂ -typecompounds (Chart E) or 5,6-dehydro-PG₂ -type compounds (Chart F)depending on whether the --C.tbd.C-- bond of XXVI is reduced tocis--CH=CH--. When a PG₂ -type compound is desired, XXVI is reduced tocis-olefin XXVIII (Chart B) with hydrogen and a catalyst which catalyzeshydrogenation of --C.tbd.C-- only to cis--CH=CH--. Such catalysts andprocedures are well known to the art. See, for example, Fieser et al.,"Reagents for Organic Synthesis", pp. 566-567; John Wiley & Sons, Inc.,New York, N.Y. (1967). Palladium (5%) on barium sulfate, especially inthe presence of pyridine as a diluent, is a suitable catalyst for thispurpose.

The transformations of cyclic ketals XXVI and XVIII to glycols XXVII andXXIX, respectively, (Charts B and D) are carried out by reacting thecyclic ketal with an acid with pK less than 5. Suitable acids andprocedures for hydrolyzing cyclic ketals to glycols are known in theart. Suitable acids are formic acid and hydrochloric acid. Especiallypreferred as a diluent for this reaction is tetrahydrofuran.

The transformations of glycol-acids XXIX and XXVII to glycol-esters XXXand XXXII, respectively, (Chart D) are esterifications carried out byprocedures known in the art to be useful for transforming carboxylicacids to esters --COOR₁₄ wherein R₁₄ is as defined above. For example, adiazohydrocarbon, e.g., diazomethane, advantageously in diethyl ethersolution, is reacted with the acid to produce the ester, e.g., themethyl ester, by known procedures. When R₁₄ is ethyl substituted with 3chloro, 2 or 3 bromo, or 1, 2, or 3 iodo, the glycol acid is reactedwith the appropriate haloethanol, e.g., β,β,β-trichloroethanol when R₄is to be --CH₂ CCl₃, in the presence of a carbodiimide, e.g.,dicyclohexylcarbodiimide, and a base, e.g., pyridine. This mixture,advantageously with an inert diluent, e.g., dichloromethane, usuallyproduces the desired haloethyl ester within several hours at about 25°C. The other esters within the scope of R₁₄ in formulas XXX and XXXIIare prepared by procedures known to the art.

The bis-alkanesulfonic acid esters XXXI and XXXIII (Chart D) areprepared by reacting glycol-esters XXX and XXXII, respectively, with analkylsulfonyl chloride or bromide, or with an alkanesulfonic acidanhydride, the alkyl in each containing one to 5 carbon atoms,inclusive. Alkylsulfonyl chlorides are preferred for this reaction. Thereaction is carried out in the presence of a base to neutralize thebyproduct acid. Especially suitable bases are tertiary amines, e.g.,dimethylaniline or pyridine. It is usually sufficient merely to mix thetwo reactants and the base, and maintain the mixture in the range 0° to25° C. for several hours. The formula XXXI and XXXIII bis-sulfonic acidesters are then isolated by procedures known to the art.

Referring now to Chart E, bis-sulfonic acid esters XXXI are transformedeither by PGE₂ -type compounds VIII or to PGA₂ -type compounds X.Referring to Chart F, bis-sulfonic acid esters XXXIII are transformedeither to 5,6-dehydro-PGE₂ -type compounds XII or to 5,6-dehydro-PGA₂-type compounds XIV.

The transformations of XXXI and XXXIII to VIII and XII, respectively,are carried out by reacting XXXI and XXXIII with water in the rangeabout 0° to about 60° C. In making racemic PGE₂ or 5,6-dehydro-PGE₂,usually 25° C. is a suitable reaction temperature, the reaction thenproceeding to completion in about 5 to 10 hours. It is advantageous tohave a homogenous reaction mixture. This is accomplished by addingsufficient of a water-soluble organic diluent which does not enter intothe reaction. Acetone is a suitable diluent. The desired product isisolated by evaporation of excess water and diluent if one is used. Theresidue contains a mixture of formula VIII or formula XII isomers whichdiffer in the configuration of the side chain hydroxy, that being eitherR or S. These are separated from byproducts and from each other bysilica gel chromatography. A usual byproduct is the mono-sulfonic acidester of formula XXXIV (Chart E) or formula XXXVII (Chart F). Thismono-sulfonic acid ester is esterified to the formula XXXI or XXXIIIbis-sulfonic acid ester in the same manner described above for thetransformation of glycol XXX or XXXII to bis-ester XXXI or XXXIII, andthus is recycled back to additional formula VIII or XII final product.

For the transformation of bis-esters XXXI and XXXIII to final productsVIII and XIII, respectively, it is preferred to use the bis-mesylesters, i.e., compounds XXXI and XXXIII wherein R₁₅ is methyl.

The configuration of the --CH₂ --CH=CH--A--COOR₁₄ moiety in the formulaXXXI bis-ester and the configuration of the --CH₂ --C.tbd.C--A--COOR₁₄moiety in the formula XXXIII bis ester do not change during thesetransformations of XXXI to VIII or XXXIII to XII. Therefore, when informula XXXI, R₂ is pentyl, R₃ and R₄ are hydrogen, and A istrimethylene, racemic PGE₂ esters are obtained when the --CH₂CH=CH--A--COOR₁₄ is attached initially in alpha configuration, andracemic 8-iso-PGE₂ esters are obtained when that moiety is attached inbeta configuration. Similarly, when in formula XXXIII, R₂ is pentyl, R₃and R₄ are hydrogen, and A is trimethylene, 5,6-dehydro-PGE₂ esters areobtained when the --CH₂ --C.tbd.C--A--COOR₁₄ moiety is attachedinitially in alpha configuration, and 8-iso-5,6-dehydro-PGE₂ esters areobtained when that moiety is attached in beta configuration.

Referring again to Charts E and F, the transformations of bis-sulfonicacid esters XXXI and XXXIII to formula X PGA_(a) -type compounds andformula XIV 5,6-dehydro-PGA₂ -type compounds, respectively, is carriedout by heating the formula XXXI or formula XXXIII bis-ester in the range40° to 100° C. with a combination of water, a base characterized by itswater solution having a pH 8 to 12, and sufficient inert water-solubleorganic diluent to form a basic and substantially homogenous reactionmixture. A reaction time of one to 10 hours is usually used. Preferredbases are the water-soluble salts of carbonic acid, especially alkalimetal bicarbonates, e.g., sodium bicarbonate. A suitable diluent isacetone. The products are isolated and separated as described above forthe transformation of bis-esters XXXI and XXXIII to final products VIIIand XII. The same mono-sulfonic acid esters XXXIV and XXXVII observed asbyproducts in those transformations are also observed during preparationof final products X and XIV. Also, as for the production of VIII and XIIthe bis-mesyl esters of XXXI and XXXIII are preferred when making X andXIV. Also as for the production of VIII and XII, during production of Xand XIV, alpha XXXI and alpha XXXIII give alpha X and alpha XIV,respectively, beta XXXI and beta XXXIII give beta X and beta XIV,respectively, and in each case, alpha and beta X and XIV, a mixture of Rand S isomers is obtained. These R and S isomer mixtures are separatedby silica gel chromatograph.

The formula VIII, X, XII, and XIV produced according to the processesoutlined in Charts B, C, D, E, and F and discussed above are all R₁₄carboxylic acid esters, wherein R₁₄ is as described above. Moreover,when these compounds are used to produce compounds of formulas IX, XI,XIII, and XV according to the processes outlined in Chart A anddiscussed above, corresponding R₁₄ esters are likely to be produced,especially in the case of the PGF₂ and 5,6-dehydro-PGF₂ compounds offormulas IX and XIII, respectively. For some of the uses describedabove, it is preferred that these formula VIII to XV compounds be infree acid form, or in salt form which requires the free acid as astarting material. The formula IX, XI, XIII, and XV R₁₄ esters areeasily hydrolyzed or saponified by the usual known procedures,especially when R₁₄ is alkyl of one to 4 carbon atoms, inclusive.Therefore it is preferred when the free acid form of compounds IX, XI,XIII, and XV is desired, that R₁₄ be such alkyl, especially methyl orethyl.

On the other hand, the formula VIII, X, XII, and XIV final products aredifficult to hydrolyze or saponify without unwanted structural changesin the desired acids. There are two other procedures useful to make thefree acid form of formula VIII, X, XII, and XIV products.

One of those procedures is applicable mainly in preparing the free acidsfrom the corresponding alkyl esters wherein the alkyl group contains oneto 8 carbon atoms, inclusive. That procedure comprises subjecting thealkyl ester corresponding to formula VIII, X, XII, or XIV to the acylaseenzyme system of a micoorganism species of Subphylum 2 of Phylum III,and thereafter isolating the acid. Especially preferred for this purposeare species of the orders Mucorales, Hypocreales, Moniliales, andActinomycetales. Also especially preferred for this purpose are speciesof the families Mucoraceae, Cunninghamellaceae, Nectreaceae,Moniliaceae, Dematiaceae, Tuberculariaceae, Actinomycetaceae, andStreptomycetaceae. Also especially preferred for this purpose arespecies of the genera Absidia, Circinella, Gongronella, Rhizopus,Cunninghamella, Calonectria, Aspergillus, Penicillium, Sporotrichum,Cladosporium, Fusarium, Nocardia, and Streptomyces.

Examples of microorganisms falling within the scope of those preferredorders, families, and genera are listed in U.S. Pat. No. 3,290,226.

This enzymatic ester hydrolysis is carried out by shaking the formulaVIII, X, XII, or XIV alkyl ester in aqueous suspension with the enzymecontained in a culture of one of the above-mentioned microorganismspecies until the ester is hydrolyzed. A reaction temperature in therange 20° to 30° C. is usually satisfactory. A reaction time of one to20 hours is usually sufficient to obtain the desired hydrolysis.Exclusion of air from the reaction mixture, for example, with argon ornitrogen is usually desirable.

The enzyme is obtained by harvest of calls from the culture, followed bywashing and resuspension of the cells in water, and cell disintegration,for example, by stirring with glass beads or by sonic or ultrasonicvibrations. The entire aqueous disintegration mixture is used as asource of the enzyme. Alternatively and preferably, however, thecellular debris is removed by centrifugation or filtration, and theaqueous supernatant or filtrate is used.

In some cases, it is advantageous to grow the microorganism culture inthe presence of an alkyl ester of an aliphatic acid, said acidcontaining 10 to 20 carbon atoms, inclusive, and said alkyl containingone to 8 carbon atoms, inclusive, or to add such an ester to the cultureand maintain the culture without additional growth for one to 24 hoursbefore cell harvest. Thereby, the enzyme produced is sometimes made moreeffective in transforming the formula VIII, X, XII, or XIV ester to thefree acid. An example of a useful alkyl ester for this purpose is methyloleate.

Although, as mentioned above, most of the R₁₄ esters encompassed byformulas VIII, X, XII, and XIV are not easily hydrolyzed or saponifiedto the corresponding free acids, certain of those esters are transformedto free acids by another method. Those esters are the haloethyl esterswherein R₁₄ is --CH₂ CCl₃, are transformed to free acids by treatmentwith zinc metal and an alkanoic acid of 2 to 6 carbon atoms, preferablyacetic acid. Zinc dust is preferred as the physical form of the zinc.Mixing the haloethyl ester with the zinc dust at about 25° C. forseveral hours usually causes substantially complete replacement of thehaloethyl moiety of the formula VIII, X, XII, or XIV ester withhydrogen. The free acid is then isolated from the reaction mixture byprocedures known to the art. This procedure is also applicable to theproduction of the free acid form of the formula IX, XI, XIII and XVcompounds from the corresponding haloethyl esters thereof.

The preparation of these haloethyl esters is described above during thediscussion of the esterification of acids XXIV and XXVII to esters XXXand XXXII, respectively.

As described above, the alkylation of cyclic ketal-ketone XVIII toketone XIX (Chart B) usually produces a mixture of alpha and betaalkylation products with respect to the ##SPC24##

moiety. Also as described above, those two isomers lead to differentfinal products, alpha leading to the PG₂ -series and beta leading to the8-iso-PG₂ -series. If a compound in one or the other of those series ispreferred, there are two methods for favoring production of thepreferred final product.

One of those methods involves isomerization of the final product offormula VIII or formula XII wherein R₁₄ is as defined above or hydrogen.Either the alpha isomer of formula VIII or XII, or the beta isomer offormula VIII or XII is maintained in an inert liquid diluent in therange 0° to 80° C. and in the presence of a base characterized by itswater solution having a pH below about 10 until a substantial amount ofthe isomer has been isomerized to the other isomer, i.e., alpha to betaor beta to alpha. Preferred bases for this purpose are the alkali metalsalts of carboxylic acids, especially alkanoic acids of 2 to 4 carbonatoms, e.g., sodium acetate. Examples of useful inert liquid diluentsare alkanols of one to 4 carbon atoms, e.g., ethanol. This reaction atabout 25° takes about one to about 20 days. Apparently an equilibrium isestablished. The mixtures of the two isomers, alpha and beta, areseparated from the reaction mixture by known procedures, and then thetwo isomers are separated from each other by known procedures, forexample, chromatography, recrystallization, or a combination of those.The less preferred isomer is then subjected to the same isomerization toproduce more of the preferred isomer. In this manner, by repeatedisomerizations and separations, substantially all of the less preferredisomer of the formula VIII or formula XII compound is transformed tomore preferred isomer.

The second method for favoring production of a preferred final formulaVIII or formula XII isomer involves any one of the intermediates offormulas XIX, XXV, XXVI, XXVII, XXVIII, XXIX, XXX, or XXXII (Charts Band D). Either the alpha form or the beta form of one of thoseintermediates is transformed to a mixture of both isomers by maintainingone or the other isomer, alpha or beta, in an inert liquid diluent inthe presence of a base and in range 0° to 100° C. until a substantialamount of the starting isomer has been isomerized to the other isomer.Preferred bases for this isomerization are alkali metal amides, alkalimetal alkoxides, alkali metal hydrides, and triarylmethyl alkali metals.Especially preferred are alkali metal tert-alkoxides of 4 to 8 carbonatoms, e.g., potassium tert-butoxide. This reaction at about 25° C.proceeds rapidly (one minute to several hours). Apparently anequilibrium mixture of both isomers is formed, starting with eitherisomer. The isomer mixtures in the equilibrium mixture thus obtained areisolated by known procedures, and then the two isomers are separatedfrom each other by known procedures, for example, chromatography. Theless preferred isomer is then subjected to the same isomerization toproduce more of the preferred isomer. In this manner, by repeatedisomerizations and separations, substantially all of the less preferredisomer of any of these intermediates is transformed to the morepreferred isomer. Cyclic acetalketone intermediates XIX and XXV arepreferred over the other intermediates for this isomerization procedure.

The final formula VIII to XV compounds prepared by the processes of thisinvention, in free acid form, are transformed to pharmacologicallyacceptable salts by neutralization with appropriate amounts of thecorresponding inorganic or organic base, examples of which correspond tothe cations and amines listed above. These transformations are carriedout by a variety of procedures known in the art to be generally usefulfor the preparation of inorganic, i.e., metal or ammonium, salts, amineacid addition salts, and quaternary ammonium salts. The choice ofprocedure depends in part upon the solubility characteristics of theparticular salt to be prepared. In the case of the inorganic salts, itis usually suitable to dissolve the formula VIII to XV acid in watercontaining the stoichiometric amount of a hydroxide, carbonate, orbicarbonate corresponding to the inorganic salt desired. For example,such use of sodium hydroxide, sodium carbonate, or sodium bicarbonategives a solution of the sodium salt. Evaporation of the water oraddition of a water-miscible solvent of moderate polarity, for example,a lower alkanol or a lower alkanone, gives the solid inorganic salt ifthat form is desired.

To produce an amine salt, the formula VIII to XV acid is dissolved in asuitable solvent of either moderate or low polarity. Examples of theformer are ethanol, acetone, and ethyl acetate. Examples of the latterare diethyl ether and benzene. At least a stoichiometric amount of theamine corresponding to the desired cation is then added to thatsolution. If the resulting salt does not precipitate, it is usuallyobtained in solid form by addition of a miscible diluent of low polarityor by evaporation. If the amine is relatively volatile, any excess caneasily be removed by evaporation. It is preferred to use stoichiometricamounts of the less volatile amines.

Salts wherein the cation is quaternary ammonium are produced by mixingthe formula VIII to XV acid with the stoichiometric amount of thecorresponding quaternary ammonium hydroxide in water solution, followedby evaporation of the water.

The invention can be more fully understood by the following examples andpreparations:

All temperatures are in degrees centigrade.

Infrared absorption spectra are recorded on a Perkin-Elmer model 421infrared spectrophotometer. Except when specified otherwise, undiluted(neat) samples are used.

NMR spectra are recorded on a Varian A-60 spectrophotometer ondeuterochloroform solutions with tetramethylsilane as an internalstandard (downfield).

Mass spectra are recorded on an Atlas CH-4 mass spectrometer with a TO-4source (ionization voltage 70 ev).

PREPARATION 1 Endo-bicyclo[3.1.0]hexan-3ol-6-carboxylic acid methylester

A mixture of endo-bicyclo[3.1.0]hex-2-ene-6-carboxylic acid methyl ester(103 g.) and anhydrous diethyl ether (650 ml.) is stirred under nitrogenand cooled to -5° C. A one molar solution (284 ml.) of diborane intetrahydrofuran is added dropwise during 30 minutes while keeping thetemperature below 0° C. The resulting mixture is then stirred andallowed to warm to 25° C. during 3 hours. Evaporation under reducedpressure gives a residue which is dissolved in 650 ml. of anhydrousdiethyl ether. The solution is cooled to 0° C., and 3 normal aqueoussodium hydroxide solution (172 ml.) is added dropwise under nitrogen andwith vigorous stirring during 15 minutes, keeping the temperature at 0°to 5° C. Next, 30% aqueous hydrogen peroxide (94 ml.) is added dropwisewith stirring during 30 minutes at 0° to 5° C. The resulting mixture isstirred an hour while warming to 25° C. Then, 500 ml. of saturatedaqueous sodium chloride solution is added, and the diethyl ether layeris separated. The aqueous layer is washed with four 200 ml. portions ofethyl acetate, the washings being added to the diethyl ether layer,which is then washed with saturated aqueous sodium chloride solution,dried, and evaporated to give 115 g. of a residue. This residue isdistilled under reduced pressure to give 69 g. of a mixture of themethyl esters of endo-bicyclo[3.1.0] hexan-3-ol-6-carboxylic acid andendo-bicyclo[3.1.0] hexan-2-ol-6-carboxylic acid; b.p. 86°-95° C. at 0.5mm.

PREPARATION 2 Endo-bicyclo[3.1.0] hexan-3-ol-6-carboxylic acid methylester tetrahydropyranyl ether

The 2-ol and 3-ol mixture (66 g.) obtained according to Preparation 1 in66 ml. of dihydropyran is stirred and cooled at 15°-20° C. duringaddition of 3 ml. of anhydrous diethyl ether saturated with hydrogenchloride. The temperature of the mixture is then kept in the range 20°to 30° C. for one hour with cooling, and is then kept at 25° for 15hours. Evaporation gives a residue which is distilled under reducedpressure to give 66 g. of a mixture of the methylesters-tetrahydropyranyl ethers of endo-bicyclo[3.1.0]hexan-3-ol-6-carboxylic acid and endo-bicyclo[3.1.0]hexan-2-ol-6-carboxylic acid; b.p. 96°-104° C. at 0.1 mm.

PREPARATION 3 Endo-6-hydroxymethylbicyclo[3.1.0]hexan-3-ol-3-tetrahydropyranyl ether

A solution of the mixture (69 g.) of products obtained according toPreparation 2 in 300 ml. of anhydrous diethyl ether is added dropwiseduring 45 minutes to a stirred and cooled mixture of lithium aluminumhydride (21 g.) in 1300 ml. of anhydrous diethyl ether under nitrogen.The resulting mixture is stirred 2 hours at 25° C., and is then cooledto 0° C. Ethyl acetate (71 ml.) is added, and the mixture is stirred 15minutes. Water (235 ml.) is then added, and the diethyl ether layer isseparated. The water layer is washed twice with diethyl ether and twicewith ethyl acetate. A solution of Rochelle salts is added to the aqueouslayer, which is then saturated with sodium chloride and extracted twicewith ethyl acetate. All diethyl ether and ethyl acetate solutions arecombined, washed with saturated aqueous sodium chloride solution, dried,and evaporated to give 61 g. of a mixture of the 3-tetrahydropyranylethers of endo-6-hydroxymethylbicyclo[3.1.0] hexan-3-ol andendo-6-hydroxymethylbicyclo[3.1.0] hexan-2-ol.

PREPARATION 4 Endo-bicyclo[3.1.0] hexan-3-ol-6-carboxaldehyde3-tetrahydropyranyl ether

A solution of the mixture (34 g.) of products obtained according toPreparation 3 in 1000 ml. of acetone is cooled to -10° C. Jones reagent(75 ml. of a solution of 21 g. of chromic anhydride, 60 ml. of water,and 17 ml. of concentrated sulfuric acid), precooled to 0° C., is addeddropwise with stirring during 10 minutes at -10° C. After 10 minutes ofadditional stirring at -10° C., isopropyl alcohol (35 ml.) is addedduring 5 minutes, and stirring is continued for 10 minutes. The reactionmixture is then poured into 8 l. of an ice and water mixture. Theresulting mixture is extracted 6 times with dichloromethane. Thecombined extracts are washed with aqueous sodium bicarbonate solution,dried, and evaporated to give 27 g. of a mixture of thetetrahydropyranyl ethers of endo-bicyclo[3.1.0]hexan-3-ol-6-carboxaldehyde and endo-bicyclo[3.1.0]hexan-2-ol-6-carboxaldehyde.

PREPARATION 5 Endo-6-(cis- andtrans-1-heptenyl)-bicyclo[3.1.0]hexan-3-ol tetrahydropyranyl ether

A mixture of hexyl bromide (100 g.), triphenylphosphine (160 g.), andtoluene (300 ml.) is stirred and heated at reflux for 7 hours. Themixture is then cooled to 10° C., and the crystals which separate arecollected by filtration, washed with toluene, and dried to give 147 g.of hexyltriphenylphosphonium bromide; m.p. 197°-200°C.

A mixture of hexyltriphenylphosphonium bromide (102 g.) and benzene(1200 ml.) is stirred under nitrogen during addition of a solution ofbutyl lithium in hexane (146 ml. of a 15% solution - w/v). The resultingmixture is stirred 30 minutes. Then a solution of the mixture (27 g.) ofproducts obtained according to Preparation 4 in 300 ml. of benzene isadded dropwise with stirring during 30 minutes. The mixture is heatedand stirred at 70° C. for 2.5 hours, and then is cooled to 25° C. Theresulting precipitate is collected by filtration and washed withbenzene. The filtrate and benzene wash are combined, washed with water,dried, and evaporated to give 58 g. of a mixture of thetetrahydropyranyl ethers of endo-6-(cis- andtrans-1-heptenyl)-bicyclo[3.1.0]hexan-3-ol and endo-6-(cis-andtrans-1-heptenyl)-bicyclo[3.1.0]hexan-2-ol.

PREPARATION 6 Endo-6-(cis- andtrans-1-heptenyl)-bicyclo[3.1.0]hexan-3-ol

Oxalic acid (3 g.) is added to a solution of the mixture (58 g.) ofproducts obtained according to Preparation 5 in 1500 ml. of methanol.The mixture is heated under reflux with stirring for 1.5 hours.Evaporation under reduced pressure gives an oil which is dissolved indichloromethane. That solution is washed with aqueous sodium bicarbonatesolution, dried, and evaporated under reduced pressure. The residue isdissolved in an isomeric hexane mixture (Skellysolve B), andchromatographed on 600 g. of wet-packed silica gel. The column is elutedwith 2.1 of Skellysolve B, and then successively with 1 l. of 2.5%, 2 l.of 5%, 2 l of 7.5%, 5 l. of 10%, and 3 l. of 15% ethyl acetate inSkellysolve B. Evaporation of the combined fractions corresponding tothe 10% and 15% ethyl acetate gives 16 g. of a mixture of endo-6-(cis-and trans-1-heptenyl)-bicyclo[3.1.0]hexan-3-ol and endo-6-(cis- andtrans-1-heptenyl)-bicyclo[3.1.0]hexan-2-ol.

PREPARATION 7 Endo-6-(cis- andtrans-1-heptenyl)--bicyclo[3.1.0]hexan-3-one (formula XVI: R₂ is pentyl,R₃ and R₄ are hydrogen, ˜ is endo)

A solution of the mixture (15 g.) of products obtained according toPreparation 6 in 450 ml. of acetone is cooled to -10° C. and stirredwhile adding 30 ml. of Jones reagent (Preparation 4) dropwise during 10minutes. The resulting mixture is stirred 10 minutes at -10° C. Then,isopropyl alcohol (15 ml.) is added, and stirring is continued for 10minutes. The mixture is poured into 2400 ml. of water. The water isextracted 5 times with dichloromethane. The combined extracts are washedwith aqueous sodium bicarbonate solution, dried, and evaporated to givean oil. The oil is chromatographed on 500 g. of silica gel wet-packedwith isomeric hexanes (Skellysolve B), eluting successively with 2 l. ofSkellysolve B, 2 l. of 2.5% ethyl acetate in Skellysolve B, and 10 l. of5% ethyl acetate in Skelly-solve B. The first 1.5 l. of the 5% ethylacetate in Skelly-solve B eluate is evaporated to give 5.9 g. ofendo-6-(cis- and trans-1-heptenyl)-bicyclo[3.1.0]hexan-3-one; R_(f) 0.62on thin layer chromatography with silica gel plates developed with 20%ethyl acetate in cyclohexane.

Following the procedures of Preparations 5, 6, and 7, but using inPreparation 5 butyl bromide, pentyl bromide, heptyl bromide, and octylbromide in place of hexyl bormide, there are obtained the 1-pentenyl,1-octenyl, and 1-nonenyl compounds corresponding to the product ofPreparation 7.

Also following the procedures of Preparations 5, 6, and 7, but using inPreparation 5, primary bromides of the formula X--(CH₂)_(d) --CH₂ Br,wherein d is one, 2, 3, or 4, and X is isobutyl, tert-butyl,3,3-difluorobutyl, 4,4-difluorobutyl, and 4,4,4-trifluorobutyl, in placeof hexyl bromide, there are obtained compounds corresponding to theproduct of Preparation 7 with X--(CH₂)_(d) --CH=CH-- in place of the1-heptenyl moiety.

Also following the procedures of Preparations 5, 6, and 7 but using inPreparation 5 the other primary and secondary bromides of the formula##STR15## wherein R₂ and R₃ are as defined above in place of hexylbromide, there are obtained compounds corresponding to the products ofPreparation 7 with ##STR16## in place of the 1-heptenyl moiety.

Also following the procedures of Preparations 5, 6, and 7 but using inPreparation 5, bicyclo[3.1.0]hexane reactants with ##STR17## in place of##STR18## wherein R₄ is as defined above, there are obtained compoundscorresponding to the product or Preparation 7 with ##STR19## in place ofthe 1-heptenyl moiety. These different bicyclo[3.1.0]hexane reactantsare prepared from the aldehyde product of Preparation 4 or the esterproduct of Preparation 3 by well known procedures. See, for example, theabove-cited Belgian Patent No. 702,477.

Also following the procedures of Preparations 5, 6, and 7 but using inPreparation 5, bicyclo[3.1.0]hexane reactants with ##STR20## in place of##STR21## and also butyl bromide, pentyl bromide, heptyl bromide, octylbromide of the formula X--(CH₂)_(d) --CH₂ Br (as above defined), andprimary and secondary bromides of the formula ##STR22## (as abovedefined), there are obtained compounds corresponding to the product ofPreparation 7 with 1-pentenyl, 1-hexenyl, 1-octenyl, and 1-nonenyl, eachsubstituted with R₄ at the 1-position, X--(CH₂)_(d) --CH=CR₄ -- , and##STR23## in place of the 1-heptenyl moiety.

Also following the procedure of Preparations 5, 6, and 7 but using inPreparation 5, exo-bicyclo[3.1.0]hexane reactants in place of each ofthe endo reactants defined in Preparation 5 and after Preparation 7, theexo compound corresponding to the endo product of Preparation 7 and toeach of the endo products defined after Preparation 7 are obtained. Thenecessary exo bicyclo[3.1.0]-hexane reactants are prepared as describedin Belgian Patent No. 702,477.

By the above-described procedures, each of the reactants encompassed byformula XVI, above, is prepared.

PREPARATION 8 Endo-6-(1,2-dihydroxyheptyl)-bicyclo[3.1.0]hexan-3-one(formula XVII: R₂ is pentyl, R₃ and R₄ are hydrogen, ˜is endo).

A solution of potassium chlorate (1.0 g.) and osmium tetroxide (0.065g.) in 25 ml. of water is added with stirring to a solution of theproduct (1.0 g.) of Preparation 7. The mixture is stirred vigorously for5 hours at 50° C. Then, the nearly colorless mixture is concentratedunder reduced pressure. The residue is extracted repeatedly withdichloromethane, and the combined extracts are dried and evaporated togive 1.2 g. of a dark oil. This oil is chromatographed on 100 g. ofsilica gel, and eluted successively with 300 ml. of 10% ethyl acetate ina mixture of isomeric hexanes (Skellysolve B), with 500 ml. of 25% ethylacetate is Skellysolve B, and then with 50% ethyl acetate in SkellysolveB, collecting 100 ml. eluate fractions. Fractions 13-19 (50% ethylacetate) were combined and evaporated to dryness to give 867 mg. ofendo-6-(1,2-dihydroxyheptyl)-bicyclo[3.1.0]hexan-3-one.

Following the procedure of Preparation 8 but using as reactants the endoand the exo 1-pentenyl, 1-hexenyl, 1-octenyl, and 1-nonenyl compoundscorresponding to the 1-heptenyl bicyclo[3.1.0]hexane reactant ofPreparation 8, the corresponding endo and exo 1,2-dihydroxypentyl,1,2-dihydroxyhexyl, 1,2-dihydroxyoctyl, and 1,2-dihydroxynonylbicyclo[3.1.0]hexane products are obtained.

Also following the procedure of Preparation 8 but using as reactants theendo and the exo compounds with X--(CH₂)_(d) --CH=CH-- in place of the1-heptenyl moiety of the reactant of Preparation 8, the correspondingX--(CH₂)_(d) --CHOH--CHOH-bicyclo[3.1.0]hexane products are obtained.

Also following the procedure of Preparation 8 but as reactants using theendo and the exo compounds with ##STR24## in place of the 1-heptenylmoiety of the reactant of Preparation 8, the corresponding ##STR25##products are obtained.

PREPARATION 9 1-Tetrahydropyranyloxy-4-bromobutane (Formula XXIII: A istrimethylene)

Concentrated hydrobromic acid (75 drops of 48%) is added with stirringto a mixture of 4-bromobutanol (150 ml.) and dihydropyran (300 ml.) atρ°. This mixture is stirred and allowed to warm slowly to 25° C. during15 hours. Evaporation under reduced pressure gives a residue which isdivided into two equal parts, each part being chromatographed on 1.5 kg.of silica gel, each column being eluted with 7.5 l. of 5% ethyl acetatein Skellysolve B, and then with 4 l. of 75.% ethyl acetate inSkellysolve B, collecting 500 ml. fractions. Fractions 5-11 from eachcolumn are evaporated to give a total of 240 g. of1-tetrahydropyranyloxy-4-bromobutane.

PREPARATION 10 7-Tetrahydropyranyloxyhept-2-yne-1-ol (Formula XXII: A istrimethylene)

Lithium metal (7.7 g.) is added in small pieces with stirring to asolution of ferric nitrate (300 mg.) in 1 l. of liquid ammonia. Themixture is then stirred under reflux until the blue color is replaced bya pale grey color. Then, a solution of propargyl alcohol (28 g.) in 250ml. of diethyl ether is added slowly with stirring. After stirring 2hours under reflux, a solution of 1-tetrahydropyranyloxy-4-bromobutane(118 g.) in 250 ml. of diethyl ether is added slowly with stirring.After stirring 4 hours under reflux 300 ml. of water and then 300 ml. ofdiethyl ether are added. The mixture is stirred about 15 hours, theammonia being allowed to evaporate during that time. The diethyl etherlayer is separated, washed with water and with saturated aqueous sodiumchloride solution, dried, and evaporated under reduced pressure to givea residue. The residue is chromatographed on 4 kg. of silica gel,eluting with 8 l. 20%, 6 l. 40%, 6 l. 60%, 6 l. 80%, and 9 l. 100% ethylacetate-Skellysolve B mixtures, collecting 1.5 l. fractions. Fractions9-12 are combined and evaporated to give 56 g. of7-tetrahydropyranyloxyhept-2-yne-1-ol.

PREPARATION 11 1-Bromo-7-tetrahydropyranyloxyhept-2-yne (Formula XX: Ais trimethylene)

Menthanesulfonyl chloride (20.3 ml.) is added slowly with stirring to asolution of 7-tetrahydropyranyloxyhept-2-yne-1-ol (52.5 g.) in 400 ml.of pyridine at -20° C. The mixture is stirred one hour at -20° C., andthen is poured into a stirred mixture of 3-normal hydrochloric acid(1727 ml.) and 2540 ml. of ice water. This mixture is extracted withdiethyl ether. The extract is washed with cold one normal hydrochloricacid and then with saturated aqueous sodium chloride solution, dried,and evaporated at reduced pressure. The residue is dissolved in 500 ml.of dry acetone. The residue is dissolved in 500 ml. of dry acetone.Lithium bromide (26 g.) is added to the acetone solution, and themixture is stirred and heated at reflux one hours, and then kept at 25°C. for 15 hours. The acetone is evaporated under reduced pressure, andthe residue is extracted with diethyl ether. The diethyl ether extractis washed with water and then three times with saturated aqueous sodiumchloride solution, dried, and evaporated. The residue is chromatographedon 3.5 kg. of silica gel, eluting with 24 l. of 10% ethyl acetate inSkellysolve B, collecting 1.5 l. fractions. Fractions 5-10 are combinedand evaporated to give 25 g. of1-bromo-7-tetrahydropyranyloxyhept-2-yne.

Following the procedures of Preparations 9, 10, and 11 but using inPreparation 9, omega-bromoalcohols of the formula Br--(CH₂)_(b) --Z--CH₂OH wherein b is zero, one, 2, or 3, and Z is ethylene substituted by oneor 2 fluoro, methyl, or ethyl, or by one alkyl of 3 or 4 carbon atoms,in place of 4-bromobutanol, there are obtained compounds correspondingto the product of Preparation 11 with --(CH₂)_(b) --Z in place oftrimethylene.

Also following the procedures of Preparations 9, 10, and 11 but using inPreparation 9, omega-bromoalcohols of formula XXIV (Chart C), i.e.,Br--A--CH₂ OH, wherein A is as defined above, in place of4-bromobutanol, there are obtained compounds corresponding to theproduct of Preparation 11 with --A-- in place of trimethylene.

EXAMPLE 1 Endo-6-(1,2-dihydroxyheptyl)-bicyclo[3.1.0]-hexan-3-oneacetonide (Formula XVIII: R₂ is pentyl, R₃ and R₄ are hydrogen, R₁₂ andR₁₃ are methyl,˜is endo)

A solution of the product (8.41 g.) of Preparation 8 and 700 mg. ofpotassium bisulfate in 140 ml. of acetone is stirred at 25° C. for 64hours. Then, sodium carbonate monohydrate (710 mg.) is added, and themixture is stirred 10 minutes. The acetone is evaporated at reducedpressure, and water is added. The aqueous solution is extractedrepeatedly with dichloromethane, and the extracts are combined, washedwith water, dried, and evaporated to give 9.3 g. of an oil. The oil ischromatographed on 400 g. of silica gel, being eluted with 2 l. of 10%ethyl acetate in Skellysolve B, and then with 4 l. of 15% ethyl acetatein Skellysolve B. The 15% ethyl acetate eluates are evaporated to give7.4 g. of endo-6-(1,2-dihydroxyheptyl)-bicyclo[3.1.0]hexan-3-oneacetonide; infrared absorption at 3000, 1745, 1370, and 1045 cm⁻ ¹ ; NMRpeaks at 4.2-3.8 (multiplet), 3.5 (doublet), 2.9-2.0 (multiplet), 1.25(singlet), and 0.91 (triplet)δ.

Following the procedure of Example 1 but using as reactants the endo andthe exo 1,2-dihydroxypentyl, 1,2-dihydroxyhexyl, 1,2-dihydroxyoctyl, and1,2-dihydroxynonyl compounds corresponding to the 1,2-dihydroxyheptylbicyclo[3.2.1]hexane reactant of Example 1, the corresponding acetonidesare obtained.

Also following the procedure of Example 1 but using as reactants theendo and exo compounds with X--(CH₂)_(d) --CHOH--CHOH-- in place of the1,2-dihydroxyheptyl moiety of the reactant of Example 1, thecorresponding acetonides are obtained.

Also following the procedure of Example 1 but using as reactants theendo and exo compounds with ##STR26## in place of the1,2-dihydroxyheptyl of the reactant of Example 1, the correspondingacetonides are obtained.

EXAMPLE 2Endo-6-(1,2-dihydroxyheptyl)-2-(7-hydroxyhept-2-yn-α-yl)-bicyclo[3.1.0]hexan-3-oneacetonide (Formula XXV: R₂ is pentyl, R₃ and R₄ are hydrogen, R₁₂ andR₁₃ are methyl, A is trimethylene,˜is endo and alpha)

A solution of potassium tert-butoxide (3.15 g.) in 100 ml. of drytetrahydrofuran is added gradually during 2 hours to a solution ofendo-6-(1,2-dihydroxyheptyl)-bicyclo[3.1.0]hexan-3-one acetonide (7.0g.) and 1-bromo-7-tetrahydropyranyloxyhept-2-yne (17.5 g.) in 125 ml. ofdry tetrahydrofuran at about 25° C. Water (200 ml.), and then ethylacetate (200 ml.) are added, and the organic layer is washed withsaturated aqueous sodium chloride solution, dried, and evaporated togiveendo-6-(1,2-dihydroxyheptyl)-2-(7-tetrahydropyranyloxyhept-2-yn-α-yl)-bicyclo[3.1.0]hexan-3-oneacetonide in the form of a yellow oil.

The yellow oil is dissolved in 450 ml. of methanol, and oxalic acid (7.5g.) is added. This solution is stirred at 25° C. for 4.5 hours. Then,sodium bicarbonate (10 g.) is added, and the mixture is concentrated toa small volume and taken up in ethyl acetate. The ethyl acetate solutionis washed with water, dried, and evaporated. The residue ischromatographed on one kg. of magnesium trisilicate (Florisil), elutingwith 4.1. each of 5, 10, 15, 20, 25, and 50% acetone in Skelly-solve B,collecting 750 ml. fractions. Fractions 11-16 are combined andevaporated to give 3.65 g. ofendo-6-(1,2-dihydroxyheptyl)-2-(7-hydroxyhept-2-yn-α-yl)-bicyclo[3.1.0]hexan-3-oneacetonide; infrared absorption at 3300 and 1745 cm⁻ ¹.

Following the procedure of Example 2 but using excess potassiumtert-butoxide (9 g.) and maintaining the reaction mixture for 8 hours at25° C. before the addition of water, the product obtained containssubstantial amounts of the beta isomer of the Example 2 product, withrespect to the --CH₂ --C.tbd.C--(CH₂)₃ -- CH₂ OH chain. This beta isomeris separated from the alpha isomer, which is also present, by silica gelchromatography with mixtures of ethyl acetate and Skellysolve B.

Following the procedure of Example 2 but using as alkylating agents,compounds of the formula ##SPC25##

wherein Hal is bromine or iodine, and b and Z are as defined above, inplace of the 1-bromo-7-tetrahydropyranyloxyhept-2-yne reactant ofExample 2, there are obtained compounds corresponding to the alphaproduct of Example 2 with --CH₂ --C.tbd.C--(CH₂)_(b) --Z--CH₂ OH inplace of --CH₂ --C.tbd.C--(CH₂)₃ --CH₂ OH. As for Example 2, with excessbase and a longer reaction time, the products also contain substantialamounts of the corresponding beta isomer which is separated from thealpha isomer as described above.

Also following the procedure of Example 2 but using as alkylatingagents, compounds of the formula ##SPC26##

wherein Hal and A are as defined above, there are obtained compoundscorresponding to the alpha product of Example 2 with --CH₂--C.tbd.C--A--CH₂ OH in place of --CH₂ --C.tbd.C--(CH₂)₃ --CH₂ OH. Asfor Example 2, with excess base and a longer reaction time, the productsalso contain substantial amounts of the corresponding beta isomer whichis separated from the alpha isomer as described above.

Also following the procedure of Example 2 but using asbicyclo[3.1.0]hexane reactants, endo and exo compounds with1,2-dihydroxypentyl, 1,2-dihydroxyhexyl, 1,2-dihydroxyoctyl,1,2-dihydroxynonyl, X--(CH₂)_(d) --CHOH--CHOH--, and ##STR27## all inacetonide form, wherein d, X, R₂, R₃ and R₄ are as defined above, inplace of the 1,2-dihydroxyheptyl acetonide moiety of the Example 2reactant, there are obtained compounds corresponding to the alphaproduct of Example 2 with one of those acetonide moieties in place ofthe 1,2-dihydroxyheptyl acetonide moiety of the Example 2 product. Asfor Example 2, with excess base and a longer reaction time, the productsalso contain substantial amounts of the corresponding beta isomer whichis separated from the alpha isomer as described above.

Also following the procedure of Example 2 but using in combination, eachof the above-defined alternative alkylating agents and each of theabove-defined alternative bicyclo[3.1.0]-hexane reactants, there areobtained compounds corresponding to the alpha product of Example 2 butdifferent therefrom with respect to both the acetonide moiety and theacetylenic moiety. As for Example 2, with excess base and a longerreaction time, the products also contain substantial amounts of thecorresponding beta isomer which is separated from the alpha isomer asdescribed above.

EXAMPLE 3Endo-6-(1,2-dihydroxyheptyl)-2-(6-carboxyhex-2-yn-α-yl)-bicyclo[3.1.0]hexan-3-oneAcetonide (Formula XXVI: R₂ is pentyl, R₃ and R₄ are hydrogen, R₁₂ andR₁₃ are methyl, A is trimethylene,˜ is endo and alpha)

Jones reagent (Preparation 4) is slowly added (10 minutes) to a solutionofendo-6-(1,2-dihydroxyheptyl)-2-(7-hydroxyhept-2-yn-α-yl)-bicyclo[3.1.0]hexan-3-oneacetonide (3.65 g.) in 500 ml. of acetone at 0° C. until the solutionhas a permanent pale yellow color. Then, isopropyl alcohol is addeduntil the yellow color changes to green to destroy the excess chromicacid. The reaction mixture is evaporated under reduced pressure, wateris added, and the mixture is extracted repeatedly with ethyl acetate.The combined ethyl acetate extracts are washed with water and then withsaturated aqueous sodium chloride solution, dried and evaporated to giveendo-6-(1,2-dihydroxyheptyl)-2-(6-carboxyhex-2-yn-α-yl)-bicyclo[3.1.0]hexan-3-oneacetonide; infrared absorption at 3400-2500, 2250, 1750, 1720, 1380,1250, 1160, 1050, 880, 850, and 815 cm⁻ ¹.

Following the procedure of Example 3, the beta isomer of the Example 3bicyclo[3.1.0]hexane reactant is oxidized to the beta isomer of theExample 3 product.

Also following the procedure of Example 3, each of the endo and exo,alpha and beta compounds defined above after Example 2 is oxidized to aproduct corresponding to the product of Example 3.

EXAMPLE 4Endo-6-(1,2-dihydroxyheptyl)-2-(6-carboxyhex-2-en-α-yl)-bicyclo[3.1.0]hexan-3-oneAcetonide (Formula XXVIII: R₂ is pentyl, R₃ and R₄ are hydrogen, R₁₂ andR₁₃ are methyl, A is trimethylene, ˜ is endo and alpha)

A solution ofendo-6-(1,2-dihydroxyheptyl)-2-(6-carboxyhex-2-yn-α-yl)-bicyclo[3.1.0]hexan-3-oneacetonide (500 mg.) in 10 ml. of pyridine is hydrogenated in thepresence of a 5% palladium of barium sulfate catalyst (150 mg.) at 25°and atmospheric pressure. During 318 minutes, 90.6 ml. of hydrogen isabsorbed. The mixture is filtered and evaporated to a smaller volume.Ethyl acetate is added, and the remaining pyridine is removed byaddition of ice and 3 normal hydrochloric acid. The ethyl acetate layeris washed with one normal hydrochloric acid and then with saturatedaqueous sodium chloride solution, dried, and evaporated to giveendo-6-(1,2-dihydroxyheptyl)-2-(6-carboxyhex-2-en-α-yl)-bicyclo[3.1.0]hexan-3-oneacetonide.

The same ethylenic hydrogenation product obtained as described abovefrom 4.0 g. of the same acetylenic reactant is chromatographed on 250 g.of silica gel which has been previously acid-washed to pH 4 (SilicarCC4, 100-200 mesh, Mallinckrodt Co.). The column is eluted with 3 l. ofa 25-75% ethyl acetate-Skellysolve B gradient, collecting 100 ml.fractions. Fractions 2-8 are combined and evaporated to give 1.8 g. ofthe sameendo-6-(1,2-dihydroxyheptyl)-2-(6-carboxyhex-2-en-α-yl)-bicyclo[3.1.0]hexan-3-oneacetonide; infrared absorption at 3500-2500, 1745, 1710, and 1020 cm⁻ ¹; NMR peaks at 5.5 (multiplet), 4.2-3.3, 1.45, 1.25, and 0.9 (triplet)δ.

Following the procedures of Example 4, the beta isomer of the Example 4acetylenic bicyclo[3.1.0]hexane reactant is hydrogenated to the betaisomer of the Example 4 ethylenic bicyclo[3.1.0]hexane product.

Also following the procedures of Example 4, each of the endo and exo,alpha and beta acetylenic compounds defined above after Example 3 ishydrogenated to an ethylenic acetonide product corresponding to theproduct of Example 4.

EXAMPLE 5Endo-6-(1,2-dihydroxyheptyl)-2-(6-carboxyhex-2-en-α-yl)-bicyclo[3.1.0]hexan-3-one(Formula XXIX: R₂ is pentyl, R₃ and R₄ are hydrogen, A is trimethylene,˜ is endo and alpha)

Concentrated hydrochloric acid (2.5 ml.) is added to a solution ofendo-6-(1,2-dihydroxyheptyl)-2-(6-carboxyhex-2-en-α-yl)-bicyclo[3.1.0]hexan-3-oneacetonide (2.0 g.) in a mixture of 55 ml. of tetrahydrofuran and 2.5 ml.of water. The mixture is stirred at 25° C. under nitrogen for 5 hours.The tetrahydrofuran is then evaporated under reduced pressure, and theresidue is extracted with ethyl acetate. The extract is washed withsaturated aqueous sodium chloride solution, dried, and evaporated togiveendo-6-(1,2-dihydroxyheptyl)-2-(6-carboxyhex-2-en-α-yl)-bicyclo[3.1.0]hexan-3-onein the form of a pale yellow oil.

EXAMPLE 6Endo-6-(1,2-dihydroxyheptyl)-2-(6-carboxyhex-2-en-α-yl)-bicyclo[3.1.0]hexan-3-one(Formula XXIX: R₂ is pentyl, R₃ and R₄ are hydrogen, A is trimethylene,˜ is endo and alpha)

Endo-6-(1,2-dihydroxyheptyl)-2-(6-carboxyhex-2-en-α-yl)-bicyclo[3.1.0]hexan-3-oneacetonide (2.0 g.) is dissolved in 98% formic acid (9 ml.). The solutionis diluted with 6 ml. of water, and the mixture is stirred 2 hours at25° C., and then extracted repeatedly with ethyl acetate. The combinedextracts are washed successively with water, aqueous sodium bicarbonatesolution, and saturated aqueous sodium chloride solution, dried, andevaporated. The residue is dissolved in 50 ml. of methanol, 10 ml. ofsaturated aqueous sodium bicarbonate solution is added, and the mixtureis kept 15 hours at 25° C. This mixture is then evaporated under reducedpressure, and the residue is acidified with dilute hydrochloric acid andextracted with ethyl acetate. The extract is washed with water and thenwith saturated aqueous sodium chloride solution, dried, and evaporatedto giveendo-6-(1,2-dihydroxyheptyl)-2-(6-carboxyhex-2-en-α-yl)-bicyclo[3.1.0]hexan-3-one.

Following the procedures of Examples 5 or 6, the beta isomer of theExample 5 or 6 ethylenic bicyclo[3.1.0]hexane acetonide reactant ishydrolyzed to the beta isomer of the Example 5 or 6 ethylenicbicyclo[3.1.0]hexane glycol product.

Also following the procedures of Examples 5 or 6, each of the endo andexo, alpha and beta ethylenic acetonide compounds defined above afterExample 4 is hydrolyzed to an ethylenic glycol product corresponding tothe product of Examples 5 and 6.

EXAMPLE 7Endo-6-(1,2-dihydroxyheptyl)-2-(6-carboxyhex-2-yn-α-yl)-bicyclo[3.1.0]hexan-3-one(Formula XXVII: R₂ is pentyl, R₃ and R₄ are hydrogen, A is trimethylene,˜ is endo and alpha)

Concentrated hydrochloric acid (1.6 ml.) is added to a solution ofendo-6-(1,2-dihydroxyheptyl)-2-(6-carboxyhex-2-yn-α-yl)-bicyclo[3.1.0]hexan-3-oneacetonide (1.6 g.) in a mixture of 32 ml. of tetrahydrofuran and 16 ml.of water. The mixture is stirred at 25° C. under nitrogen for 15 hours.The tetrahydrofuran is then evaporated under reduced pressure, and theresidue is extracted with ethyl acetate. The extract is washed withsaturated aqueous sodium chloride solution, dried, and evaporated togiveendo-6-(1,2-dihydroxyheptyl)-2-(6-carboxyhex-2-yn-α-yl)-bicyclo[3.1.0]hexan-3-one.

EXAMPLE 8Endo-6-(1,2-dihydroxyheptyl)-2-(6-carboxyhex-2-yn-α-yl)-bicyclo[3.1.0]hexan-3-one(Formula XXVII: R₂ is pentyl, R₃ and R₄ are hydrogen, A is trimethylene,˜ is endo and alpha)

Following the procedure of Example 6 but using the acetylenic acetonidereactant of Example 7 in place of the ethylenic acetonide reactant ofExample 6,endo-6-(1,2-dihydroxyheptyl)-2-(6-carboxyhex-2-yn-α-yl)-bicyclo[3.1.0]hexan-3-oneis obtained.

Following the procedures of Examples 7 or 8, the beta isomer of theExample 7 or 8 acetylenic bicyclo[3.1.0]hexane acetonide is hydrolyzedto the beta isomer of the Example 7 or 8 acetylenic bicyclo[3.1.0]hexaneglycol product.

Also following the procedures of Examples 7 or 8, each of the endo andexo, alpha and beta acetylenic acetonide compounds defined above afterExample 3 is hydrolyzed to an acetylenic glycol product corresponding tothe product of Examples 7 and 8.

EXAMPLE 9Endo-6-(1,2-dihydroxyheptyl)-2-(6-carboxyhex-2-en-α-yl)-bicyclo[3.1.0]hexan-3-oneβ,β,β-trichloroethyl ester (Formula XXX: R₂ is pentyl, R₃ and R₄ arehydrogen, R₁₄ is β,β,β-trichloroethyl, A is trimethylene, ˜ is endo andalpha)

Successively, β,β,β-trichloroethanol (24 ml.), pyridine (12 ml.), anddicyclohexylcarbodiimide (3.2 g.) are added to a solution of theendo-6-(1,2-dihydroxyheptyl)-2-(6-carboxyhex-2-en-α-yl)-bicyclo[3.1.0]hexan-3-oneobtained from Example 5 in 120 ml. of dichloromethane. This mixture isstirred for 3 hours at 25° C. under nitrogen. Water (50 ml.) is thenadded, and the mixture is stirred 10 minutes. The dichloromethane isevaporated under reduced pressure, and the residue is extractedrepeatedly with ethyl acetate. The combined extracts are washed withice-cold 3 normal hydrochloric acid, filtering to remove precipitateddicyclohexylurea. Then, the extracts are washed with aqueous sodiumbicarbonate solution and then with saturated aqueous sodium chloridesolution, dried, and evaporated under reduced pressure. The residue ischromatographed on 400 g. of silica gel, eluting with 8 l. of a 20-100%ethyl acetate-Skellysolve B gradient, collecting 250-ml. fractions.Fractions 4-8 and 18-29 are combined, retreated with hydrochloric acidin tetrahydrofuran as in Example 5, and then with trichloroethanol,pyridine, and dicyclohexylcarbodiimide as above. Chromatography of theresidue from this second esterification as described above givesfractions 9-17 which are combined with fractions 9-17 from the firstchromatography. These combined fractions are evaporated under reducedpressure to give a residue which is chromatographed on 100 g. of silicagel impregnated with silver nitrate. Elution is with 2 l. of a 20-100%ethyl acetate-Skellysolve B gradient, collecting 50-ml. fractions.Fractions 5-9 are combined and evaporated to give 800 mg. ofendo-6-(1,2-dihydroxyheptyl)-2-(6-carboxyhept-2-en-α-yl)-bicyclo[3.1.0]hexan-3-oneβ,β,β-trichloroethyl ester; infrared absorption at 3300, 3400, 1755,1745, 1220, 1140, 1050, 935, 875, 810, and 720 cm⁻ ¹ ; NMR peaks at4.7-5.3, 4.7 (singlet), 4.2-3.2, 0.9 (triplet)δ; mass spectral molecularion peaks at 464, 466, and 468.

EXAMPLE 10Endo-6-(1,2-dihydroxyheptyl)-2-(6-carboxyhex-2-en-α-yl)-bicyclo[3.1.0]hexan-3-onemethyl ester (Formula XXX: R₂ is pentyl, R₃ and R₄ are hydrogen, R₁₄ ismethyl, A is trimethylene, and ˜ is endo and alpha)

A solution of 2 equivalents of diazomethane in 100 ml. of anhydrousdiethyl ether is added to theendo-6-(1,2-dihydroxyheptyl)-2-(6-carboxyhex-2-en-α-yl)-bicyclo[3.1.0]hexan-3-oneobtained from Example 6. This mixture is stirred at 25° C. for 15minutes. Then, the solution is evaporated, and the residue ischromatographed on 400 g. of silica gel, eluting with 8 l. of a 20-100%ethyl acetate-Skellysolve B gradient, collecting 250-ml. fractions.Fractions 9-17 are combined and evaporated under reduced pressure. Theresidue is chromatographed on 100 g. of silica gel impregnated withsilver nitrate, eluting with 2 l. of a 20-100% ethyl acetate-SkellysolveB gradient, collecting 50-ml. fractions. Fractions 5-9 are combined andevaporated to giveendo-6-(1,2-dihydroxyheptyl)-2-(6-carboxyhex-2-en-α-yl)-bicyclo[3.1.0]hexan-3-onemethyl ester.

Following the procedures of Examples 9 and 10, the beta isomer of theExample 9 or 10 ethylenic bicyclo[3.1.0]hexane glycol is esterified tothe corresponding β,β,β-trichloroethyl and methyl esters.

Also following the procedures of Examples 9 and 10, each of the endo andexo, alpha and beta ethylenic glycols defined above after Example 6 isesterified to β,β,β-trichloroethyl and methyl esters corresponding tothe esters of Examples 9 and 10.

EXAMPLE 11Endo-6-(1,2-dihydroxyheptyl)-2-(6-carboxyhex-2-yn-α-yl)-bicyclo[3.1.0]hexan-3-oneβ,β,β-trichloroethyl ester (Formula XXXII: R₂ is pentyl, R₃ and R₄ arehydrogen, R₁₄ is β,β,β-trichloroethyl, A is trimethylene, ˜ is endo andalpha)

Successively, β,β,β-trichloroethanol (9.6 ml.), pyridine (4.8 ml.), anddicyclohexylcarbodiimide (1.28 g.) are added to a solution of theendo-6-(1,2-dihydroxyheptyl)-2-(6-carboxyhex-2-yn-α-yl)-bicyclo[3.1.0]hexan-3-oneobtained from Example 7 in 48 ml. of dichloromethane. This mixture isstirred for 3 hours at 25° C. under nitrogen. Water (16 ml.) is thenadded, and the mixture is stirred 10 minutes. The dichloromethane isevaporated under reduced pressure, and the residue is extractedrepeatedly with ethyl acetate. The combined extracts are washed withice-cold one normal hydrochloric acid and then filtered. The filtrate iswashed with aqueous sodium bicarbonate solution and then with saturatedaqueous sodium chloride solution, dried and evaporated under reducedpressure. The residue is chromatographed on 150 g. of silica gel,eluting with 5 l. of a 20-100% ethyl acetate-Skellysolve B gradient,collecting 150-ml. fractions. Fractions 5-8 are evaporated under reducedpressure to give 537 mg. ofendo-6-(1,2-dihydroxyheptyl)-2-(6-carboxyhex-2-yn-α-yl)-bicyclo[3.1.0]hexan-3-oneβ,β,β-trichloroethyl ester; NMR peaks at 4.8 (singlet), 4.3-4.0(multiplet), 3.8-3.5 (multiplet), 2.4-2.1 (multiplet), and 0.9(triplet)δ.

EXAMPLE 12Endo-6-(1,2-dihydroxyheptyl)-2-(6-carboxyhex-2-yn-α-yl)-bicyclo[3.1.0]hexan-3-onemethyl ester (Formula XXXII: R₂ is pentyl, R₃ and R₄ are hydrogen, R₁₄is methyl, A is trimethylene, ˜ is endo and alpha)

Following the procedure of Example 10 but using theendo-6-(1,2-dihydroxyheptyl)-2-(6-carboxyhex-2-yn-α-yl)-bicyclo-[3.1.0]hexan-3-oneobtained from Example 8 in place of the ethylenic reactant of Example10,endo-6-(1,2-dihydroxyheptyl)-2-(6-carboxyhex-2-yn-α-yl)-bicyclo[3.1.0]hexan-3-onemethyl ester is obtained.

Following the procedures of Examples 11 and 12, the beta isomer of theExample 11 or 12 acetylenic bicyclo[3.1.0]glycol is esterified to thecorresponding β,β,β-trichloroethyl and methyl esters.

Also following the procedures of Examples 11 and 12, each of the endoand exo, alpha and beta acetylenic glycols defined above after Example 8is esterified to β,β,β-trichloroethyl and methyl esters corresponding tothe esters of Examples 11 and 12.

EXAMPLE 13 Racemic PGE₂ (S) and racemic 15-epi-PGE₂ (R)β,β,β-trichloroethyl esters

Methanesulfonyl chloride (2.5 ml.) is added dropwise to a solution ofendo-6-(1,2-dihydroxyheptyl)-2-(6-carboxyhex-2-en-α-yl)-bicyclo[3.1.0]hexan-3-oneβ,β,β-trichloroethyl ester (800 mg.) in 25 ml. of pyridine at 0° C.under nitrogen. The mixture is stirred 2 hours while slowly warming to25° C. The solution is again cooled to 0° C., a mixture of ice and wateris added (2 volumes), and the mixture is extracted repeatedly with ethylacetate. The combined extracts are washed successively with cold water,3 normal hydrochloric acid, and saturated aqueous sodium chloridesolution, dried, and evaporated under reduced pressure to giveendo-6-(1,2-dimesyloxyheptyl)-2-(6-carboxyhex-2-en-α-yl)-bicyclo[3.1.0]hexan-3-oneβ,β,β-trichloroethyl ester in the form of pale yellow oil.

The dimesylate is dissolved in acetone (72 ml.) and water (36 ml.), andthe solution is stirred under nitrogen at 25° C. for 15 hours. Theacetone is removed under reduced pressure, and the residue is extractedrepeatedly with ethyl acetate. The combined extracts are washed withsaturated aqueous sodium chloride solution, dried, and evaporated. Theresidue is chromatographed on 100 g. of silica gel, eluting with 2 l. ofa 50-100% ethyl acetate-Skellysolve B gradient, collecting 50-ml.fractions. Fractions 3-16 are combined and evaporated to give 604 mg. ofendo-6-(1-hydroxy-2-mesyloxyheptyl)-2-(6-carboxyhex-2-en-α-yl)-bicyclo[3.1.0]-hexan-3-oneβ,β,β-trichloroethyl ester, which is used in place of part of thestarting glycol in the next run. Fractions 17-19 are combined andevaporated to give 96 mg. of racemic 15-epi-PGE₂ β,β,β-trichloroethylester; NMR peaks at 5.75-5.6 (multiplet), 5.55-5.2, 4.75 (singlet),4.35-3.8 (multiplet), and 0.9 δ; mass spectrum spectral peaks at 464,466, and 468; R_(f) 0.37 on TLC with A-IX system. Fractions 33-44 arecombined and evaporated to give 100 mg. of racemic PGE₂β,β,β-trichloroethyl ester; NMR peaks at 5.65-5.4 (multiplet), 4.75(singlet), 4.35-3.8 (multiplet), and 0.9 δ; mass spectrum spectral peaksat 464, 466, and 468; R_(f) 0.26 on TLC with A-IX system.

EXAMPLE 14 Racemic PGE₂ (S) and racemic 15-epi-PGE₂ (R) methyl esters

Following the procedures of Example 13,endo-6-(1,2-di-hydroxyheptyl)-2-(6-carboxyhex-2-en-α-yl)-bicyclo[3.1.0]hexan-3-onemethyl ester is transformed first toendo-6-(1,2-di-mesyloxyheptyl)-2-(6-carboxyhex-2-en-α-yl)-bicyclo[3.1.0]hexan-3-onemethyl ester, and then with acetone and water, to a mixture of productswhich is separated as described in Example 13 to giveendo-6-(1-hydroxy-2-mesyloxyheptyl)-2-(6-carboxyhex-2-en-α-yl)-bicyclo[3.1.0]hexan-3-onemethyl ester, racemic PGE₂ methyl ester, and racemic 15-epi-PGE₂ methylester.

Following the procedures of Examples 13 and 14, the beta isomer of theExample 13 or 14 ethylenic bicyclo[3.1.0]hexane glycol ester reactant istransformed to first the corresponding intermediate ethylenicbicyclo[3.1.0]hexane dimesylate ester, and then to a mixture of thecorresponding ethylenic bicyclo-[3.1.0]hexane monomesylate, racemic8-iso-PGE₂, and racemic 8-iso-15-epi-PGE₂ β,β,β-trichloroethyl andmethyl esters, which are separated as described in Example 13.

Also following the procedures of Examples 13 and 14, each of the endoand exo, alpha and beta ethylenic glycol β,β,β-trichloroethyl and methylesters defined above after Example 10 is transformed first to adimesylate corresponding to the intermediate ethylenicbicyclo[3.1.0]hexane dimesylate ester products of Examples 13 and 14,and then to the β,β,β-trichloroethyl and methyl esters of amonomesylate, a racemic PGE₂ -type compound, and a racemic 15-epi-PGE₂-type compound, each corresponding to one of the three final products ofExamples 13 and 14.

EXAMPLE 15 Racemic 5,6-dehydro-PGE₂ (S) and racemic5,6-dehydro-15-epi-PGE₂ (R) β,β,β-trichloroethyl esters

Methanesulfonyl chloride (1 ml.) is added dropwise to a solution ofendo-6-(1,2-dihydroxyheptyl)-2-(6-carboxyhex-2-yn-α-yl)-bicyclo[3.1.0]hexan-3-oneβ,β,β-trichloroethyl ester (537 mg.) in 10 ml. of pyridine at 0° C.under nitrogen. The mixture is stirred 2 hours while slowly warming to25° C. The solution is again cooled to 0° C., a mixture of ice and wateris added, and the mixture is extracted repeatedly with ethylacetate. Thecombined extracts are washed successively with cold water, 3 normalhydrochloric acid, and saturated aqueous sodium chloride solution,dried, and evaporated under reduced pressure to giveendo-6-(1,2-dimesyloxyheptyl)-2-(6-carboxyhex-2-yn-α-yl)-bicyclo[3.1.0]hexan-3-oneβ,β,β-trichloroethyl ester.

The dimesylate is dissolved in acetone (30 ml.) and diluted with water(15 ml.). This solution is stirred under nitrogen 25° C. for 15 hours.The acetone is removed under reduced pressure, and the residue isextracted repeatedly with ethylacetate. The combined extracts are washedwith saturated aqueous sodium chloride solution, dried, and evaporated.The residue is chromatographed on 75 g. of silica gel, eluting with 1.5l. of a 50-100% ethyl acetate-Skellysolve B gradient, collecting 50-ml.fractions. Early fractions are combined and evaporated to giveendo-6-(1-hydroxy-2-mesyloxyheptyl)-2-(6-carboxyhex-2-yn-α-yl)-bicyclo[3.1.0]hexan-3-oneβ,β,β-trichloroethyl ester. Fractions 11-15 are combined and evaporatedto give 29 mg. of racemic 5,6-dehydro-15-epi-PGE₂ β,β,β-trichloroethylester; NMR peaks at 5.9-5.65, 4.8 (singlet), 4.4-4.0, 2.4-2.1(multiplet), and 0.9 (triplet)δ. Fractions 18-24 are combined andevaporated to give 28 mg. of racemic 5,6-dehydro-PGE₂β,β,β-trichloroethyl ester; NMR peaks at 5.8-5.5, 4.8 (singlet),4.4-4.0, 2.4-2.1 (multiplet), and 0.9 (triplet)δ.

EXAMPLE 16 Racemic 5,6-dehydro-PGE₂ (S) and racemic5,6-dehydro-15-epi-PGE₂ (R) methyl esters

Following the procedure of Example 15,endo-6-(1,2-dihydroxyheptyl)-2-(6-carboxyhex-2-en-α-yl)-bicyclo[3.1.0]hexan-3-onemethyl ester is transformed first to the corresponding dimesylate, andthen with acetone and water, to a mixture of products which is separatedas described in Example 15 to giveendo-6-(1-hydroxy-2-mesyloxyheptyl)-2-(6-carboxyhex-2-yn-α-yl)-bicyclo[3.1.0]hexan-3-onemethyl ester, racemic 5,6-dehydro-PGE₂ methyl ester, and racemic5,6-dehydro-15-epi-PGE₂ methyl ester.

Following the procedures of Examples 15 and 16, the beta isomer of theExample 15 or 16 acetylenic bicyclo[3.1.0]hexane glycol ester reactantis transformed first to the corresponding intermediate dimesylate, andthen to the corresponding monomesylate, racemic 5,6-dehydro-8-iso-PGE₂,and racemic 5,6-dehydro-8-iso-15-epi-PGE₂ β,β,β-trichloroethyl andmethyl esters, which are separated as described in Example 15.

Also following the procedures of Examples 15 and 16, each of the endoand exo, alpha and beta acetylenic glycol β,β,β-trichloroethyl andmethyl esters defined above after Example 12 is transformed first to adimesylate corresponding to the intermediate dimesylate products ofExamples 15 and 16, and then to the β,β,β-trichloroethyl and methylesters of a monomexylate, a racemic 5,6-dehydro-PGE₂ -type ester, and aracemic 5,6-dehydro-15-epi-PGE₂ -type ester, each corresponding to oneof the three final products of Examples 15 and 16.

EXAMPLE 17 Racemic PGE₂ (S)

Zinc dust (400 mg.) is added to a solution containing racemic PGE₂β,β,β-trichloroethyl ester (100 mg.) in 5 ml. of a mixture of aceticacid and water (9:1 v/v). This mixture is stirred under nitrogen 2 hoursat 25° C. Ethyl acetate (4 volumes) is then added, followed by additionof one normal hydrochloric acid (one volume). The ethyl acetate layer isseparated, washed with water and then with saturated aqueous sodiumchloride solution, dried, and evaporated. The residue is chromatographedon 15 g. of acid-washed silica gel (Silicar CC4), being eluted with 100ml. of 50%, 100 ml. of 80%, and 200 ml. of 100% ethyl acetate inSkellysolve B, collecting 20-ml. fractions. Fractions 13-18 are combinedand evaporated to give racemic PGE₂ ; same mobility as optically activePGE₂ and same color (with vanillin-phosphoric acid spray) on TLC silicagel and silver nitrate-impregnated silica gel plates; NMR peaks andinfrared absorption (CH₂ Cl₂ solution) same as optically active PGE₂ ;mass spectrum spectral peaks at 316, 298, 279, and 190.

EXAMPLE 18 Racemic 15-epi-PGE₂ (R)

Following the procedure of Example 17, racemic 15-epi-PGE₂β,β,β-trichloroethyl ester is transformed to 15-epi-PGE₂ ; NMR peaks at5.8-5.6 (multiplet), 5.6-5.3 (multiplet), 4.5-3.9 (multiplet), and 0.9(triplet δ.

EXAMPLE 19 Racemic 5,6-dehydro-PGE₂ (S)

Zinc dust (150 mg.) is added to a solution containing racemic5,6-dehydro-PGE₂ (28 mg.) in 1.5 ml. of a mixture of acetic acid andwater (9:1 v/v). This mixture is stirred under nitrogen for 2 hours at25° C. Ethyl acetate (4 volumes) is then added. The ethyl acetate layeris washed with one normal hydrochloric acid and then with saturatedaqueous sodium chloride solution, dried, and evaporated. Benzene isadded to the residue and then evaporated under reduced pressure. Theresidue is chromatographed on 5 g. of acid-washed silica gel (SilicarCC4), eluting with 100 ml. of 75% ethyl acetate in Skellysolve B, andthen with 100 ml. ethyl acetate, collecting 10 ml. fractions. Fractions8- 11 are combined and evaporated to give 21 mg. of crystalline racemic5,6-dehydro-PGE₂ ; m.p. 85°-90°C.; recrystallized twice from a mixtureof ethyl acetate and Skellysolve B, m.p. 89°-91°C.; mass spectrumspectral peaks at 332,314, 296, 261, and 243.

EXAMPLE 20 Racemic 5,6 -dehydro-15-epi-PGE₂ (R)

Following the procedure of Example 19, racemic 5,6-dehydro-15 -epi-PGE₂β, β, β-trichloroethyl ester is transformed to 5,6-dehydro-15-epi-PGE₂.

Following the procedures of Examples 17 and 19, the beta isomers of theβ, β, β-trichloroethyl esters of racemic PGE₂, racemic 15-epi-PGE₂,racemic 5,6-dehydro-PGE₂, and racemic 5,6-dehydro-15-epi-PGE₂ are eachtransformed to racemic 8-iso-PGE₂, racemic 8-iso-15-epi-PGE₂, racemic5,6-dehydro-8-iso-PGE₂, and racemic 5,6-dehydro-8-iso-15-epi-PGE₂,respectively.

Also following the procedure of Example 17, each of β, β,β-trichloroethyl esters of the racemic PGE₂ -type compounds and theracemic 15-epi-PGE₂ -type compounds defined above after Example 14 istransformed to the corresponding racemic PGE₂ -type acid and the racemic15-epi-PGE₂ -type acid, including the corresponding 8-iso acids.

Also following the procedure of Example 19, each of the β, β,β-trichloroethyl esters of the racemic 5,6-dehydro-PGE₂ -type compoundsand the racemic 5,6-dehydro-15-epi-PGE₂ -type compounds defined aboveafter Example 16 is transformed to the corresponding racemic5,6-dehydro-PGE₂ -type acid and the racemic 5,6-dehydro-15-epi-PGE₂-type acid, including the 8-iso acids.

EXAMPLE 21 Racemic PGE₂

A. Enzyme preparation

A medium is prepared consisting of 2% corn steep liquor (a mixture ofequal parts of cerelose and glucose) in tap water. This is brought to pH4.5 by adding hydrochloric acid, and 1% of methyl oleate is added. Four500 ml. flasks each containing 100 ml. of the above medium areinoculated with Cladosporum resinae (C1-11, ATCC 11,274) and are placedon a shaker at room temperature (about 28°C.) for 4 days. The culture isthen placed in 40 ml. centrifuge tubes and centrifuged at about 2000rmp. in a clinical centrifuge. The liquid is decanted from thecentrifuge tubes and the collected cells are washed with cold water. Thewashed cells from 2 centrifuge tubes are suspended in 50 ml. of ice cold0.05 M pH 7.0 phosphate buffer and placed in small Waring blender cupchilled with ice. Glass beads are added and the suspended cells arechurned in the blender for 15 minutes. The resulting suspension ofbroken cells is centrifuged in a clinical centrifuge at about 2000r.p.m. for 15 minutes at room temperature, then the supernatant liquidis collected. This supernatant liquid contains Cladosporium resinaeacylase and is used directly for the hydrolysis of PG₂ -type alkylesters or is stored, preferably frozen, until needed.

B. Esterase hydrolysis of racemic PGE₂ methyl ester Ten milliliters ofthe supernatant liquid containing Cladosporium resinae acylase, preparedas described in part A of this example and 50 mg. of racemic PGE₂ methylester are shaken at room temperature under nitrogen for about 19 hrs.,then 70 ml. of acetone is added and the mixture is filtered giving afiltrate and an insoluble residue. The filtrate is evaporated underreduced pressure and gives 40-50 mg. of a slightly yellow oil comprisingracemic PGE₂. Both this oil and the isoluble residue are combined andchromatographed over 10 g. of acid washed silica gel (Silic ARCC-4,Mallinckrodt). Elution is with mixed hexanes (Skellysolve B) containingincreasing amounts of ethyl acetate, collecting 50 ml. fractions asfollows:

    ______________________________________                                        Fraction                                                                              Solvent                                                               ______________________________________                                        1       Skellysolve B                                                         2       40 ml. Skellysolve B - 10 ml. ethyl acetate                           3       30 ml. Skellysolve B - 20 ml. ethyl acetate                           4       25 ml. Skellysolve B - 25 ml. ethyl acetate                           5       20 ml. Skellysolve B - 30 ml. ethyl acetate                           6       10 ml. Skellysolve B - 40 ml. ethyl acetate                           7        5 ml. Skellysolve B - 45 ml. ethyl acetate                           8       ethyl acetate                                                         9       ethyl acetate                                                         10      ethyl acetate                                                         11      ethyl acetate                                                         12      100 ml. of ethyl acetate                                              ______________________________________                                    

Fractions 6 to 12 are combined and evaporated to give racemic PGE₂ withsubstantially the same properties as that obtained according to Example17.

Following the procedure of Example 21, each of the methyl esters of thePGE₂ type and 5,6-dehydro-PGE₂ -type compounds defined above afterExamples 14 and 16 are enzymatically hydrolyzed to the correspondingfree acid.

Also following the procedure of Example 21, each of the methyl esters ofthe PGF₂ -type, PGA₂ -type, PGB₂ -type and the corresponding5,6-dehydro-PG₂ -type compounds defined hereinafter is enzymaticallyhydrolyzed to the corresponding free acid.

EXAMPLE 22 Racemic PGF₂ α and racemic PGF₂ β.

A solution of sodium borohydride (70 mg.) in 5 ml. of ice-cold methanolis added dropwise with stirring to a solution of racemic PGE₂ (22 mg.)in 1.5 ml. of methanol at 0°C. This mixture is stirred at 0°C. for 30minutes, and is then stirred and allowed to warm to 25°C. during onehour. After evaporation, water (10 ml.) is added, and the mixture isacidified with one normal hydrochloric acid, saturated with sodiumchloride, and extracted repeatedly with ethyl acetate. The combinedextracts are washed with saturated aqueous sodium chloride solution,dried, and evaporated. The residue is chromatographed on 3 g. ofacid-washed silica gel (Silicar CC4), eluting with 50 ml. of ethylacetate and then with 50 ml. of one % methanol in ethyl acetate,collecting 10 ml. fractions. Fractions 4 and 5 are combined andevaporated to give 11 mg. of racemic PGF₂.sub.α ; same mobility asoptically active PGF₂.sub.α on TLC silica gel and silver-nitrateimpregnated silica gel plates with the A IX system twice; mass spectrumspectral peaks same as for optically active PGF.sub. 2.sub.α. Fractions7-9 are combined and evaporated to give 14 mg. of racemic PGF₂.sub.β ;m.p. 85°-92°C.; recrystallized twice from ethyl acetate, m.p. 92°-93°C.;same mobility as optically active PGF₂.sub.β on TLC silica gel plates asfor PGF₂.sub.β ; mass spectrum spectral peaks same as for opticallyactive PGF₂.sub.β.

EXAMPLE 23 Racemic 15-epi-PGF₂.sub.α and racemic 15-epi-PGF₂.sub.β

Following the procedure of Example 22, 20 mg. of racemic 15-epi-PGE₂ isreduced with sodium borohydride to give racemic 15-epi-PGF₂.sub.β andracemic 15-epi-PGF₂.sub.β, separated by chromatography on Silicar CC4,eluting successively with 50, 75, and 100% ethyl acetate in SkellysolveB.

Following the procedure of Example 22, racemic 8-iso-PGE₂ and racemic8-iso-15-epi-PGE₂ are each reduced to the alpha and beta isomers ofracemic 8-iso-PGE₂ and racemic 8-iso-15-epi-PGF₂, respectively, thealpha and beta pairs being separated in each as described in Examples 22or 23.

Also following the procedure of Example 22, each of the racemic PGE₂-type compounds, 5,6-dehydro-PGE₂, 5,6-dehydro-15-epi-PGE₂,5,6-dehydro-8-iso-PGE₂, 5,6-dehydro-8-iso-15-epi-PGE₂, and each of theother 5,6-dehydro-PGE₂ -type compounds defined above is reduced to thealpha and beta isomers of the corresponding PGF₂ -type and5,6-dehydro-PGF₂ -type compound. In each case, the alpha and betaisomers are separated as described in Examples 22 or 23.

EXAMPLE 24 Racemic PGA₂ (S) and racemic 15-epi-PGA₂ (R)

Endo-6-(1,2-dimesyloxyheptyl)-2-(6-carboxyhex-2-en-α-yl)-bicyclo[3.1.0]hexan-3-oneβ,β,β-trichloroethyl ester is prepared as described in Example 13 from800 mg. of glycol.

The dimesylate is dissolved in 75 ml. of acetone to which is added 10ml. of water and 20 ml. of saturated sodium bicarbonate solution. Thismixture is refluxed under nitrogen for 4 hours. After acidification withone normal hydrochloric acid, the mixture is extracted with ethylacetate, and the extracts are washed, dried, and evaporated to give theβ,β,β-trichloroethyl ester of racemic PGA₂. That ester is transformed toracemic PGA₂ by the procedure of Example 17, the racemic PGA₂ beingpurified by the procedure of Pike et al., above cited.

Following the procedure of Example 24 and using each of the abovedefined exo and endo, alpha and beta, ethylenic and acetylenicbicyclo[3.1.0]hexane glycol β,62 ,β-trichloroethyl esters followingExamples 9, 10, 11, and 12, there are obtained each of the correspondingracemic PGA₂ -type and 5,6-dehydro-PGA₂ -type compounds including15-epi-PGA₂, 8-iso-PGA₂, 8-iso-15-epi-PGA₂, 5,6-dehydro-PGA₂,5,6-dehydro-15-epi-PGA₂, 5,6-dehydro-8-iso-PGA₂, and5,6-dehydro-8-iso-15-epi-PGA₂.

Each of the above-defined racemic PGA₂ -type compounds and5,6-dehydro-PGA₂ -type compounds is also prepared from the correspondingPGE₂ -type and 5,6-dehydro-PGA₂ -type compound by acetic aciddehydration as described by Pike et al., above cited, and in BritishSpecification No. 1,097,533.

EXAMPLE 25 Racemic PGB₂

A solution of racemic PGE₂ (200 mg.) in 100 ml. of 50% aqueous ethanolcontaining 10 grams of potassium hydroxide is kept at 25° C. for 10hours under nitrogen. Then, the solution is cooled to 10° C. andneutralized by addition of 3 normal hydrochloric acid at 10° C. Theresulting solution is extracted repeatedly with ethyl acetate, and thecombined ethyl acetate extracts are washed with water and then withsaturated aqueous sodium chloride solution, dried, and evaporated togive racemic PGB₂.

Following the procedure of Example 25, racemic PGA₂ is transformed toracemic PGB₂.

Also following the procedure of Example 25, each of the above definedPGE₂ -type compounds and each of the above-defined PGA₂ -type compoundsis transformed to the corresponding PGB₂ -type compound, including15-epi-PGB₂, 5,6-dehydro-PGB₂, and 5,6-dehydro-15-epi-PGB₂.

EXAMPLE 26 Racemic 8-iso-PGE₂ from racemic PGE₂

A solution of 1.00 g. of racemic PGE₂ and 5 g. of potassium acetate in100 ml. of 95% ethanol is allowed to stand at room temperature undernitrogen for 6 days; then is concentrated by evaporation under reducedpressure to about one third volume. The concentrated mixture is dilutedwith 75 ml. of cold water and dilute hydrochloric acid is added untilthe mixture reaches pH 3. The acidified mixture is extracted twice withethyl acetate, then is saturated with sodium chloride and extracted oncemore with ethyl acetate. The ethyl acetate extracts are combined, washedwith saturated aqueous sodium chloride, dried over sodium sulfate, andevaporated under reduced pressure, then dried under a stream of nitrogento remove acetic acid from the residue. Thin layer chromatographicanalysis shows that the residue comprises a mixture of racemic PGE₂ andracemic 8-iso PGE₂. The residue is chromatographed on 200 g. of SilicarCC4, eluting with 500 ml. 40%, 500 ml. 50%, 250 ml. 60%, and 250 ml.100% ethyl acetate in cyclohexane, collecting 50-ml. fractions.Fractions 23-25 are combined and evaporated to give racemic 8-iso-PGE₂.Fractions 27-30 are combined to give racemic PGE₂.

EXAMPLE 27 Racemic PGE₂ from racemic 8-iso-PGE₂

The procedure of Example 26 is followed, using as a starting materialracemic 8-iso-PGE₂ rather than racemic PGE₂. Substantially the sameproduct mixture is obtained.

Following the procedures of Examples 26 or 27, each of the PGE₂ -type,8-iso-PGE₂ -type, 5,6-dehydro-PGE₂ -type, and 5,6-dehydro-8-iso-PGE₂-type compounds defined above is transformed to a mixture of alpha andbeta isomers, the two isomers then being separated as described inExample 26.

EXAMPLE 28Endo-6-(1,2-dihydroxyheptyl)-2-(7-hydroxyhept-2-yn-β-yl)-bicyclo[3.1.0]hexan-3-one

Endo-6-(1,2-dihydroxyheptyl)-2-(7-hydroxyhept-2-yn-α-yl)-bicyclo[3.1.0]hexan-3-one(1.2 g.) is dissolved in 100 ml. of dry dimethoxyethane. Potassiumtert-butoxide (400 mg.) is added, and the mixture is maintained undernitrogen at 25° C. for one hour. Then, sufficient hydrochloric acid (3N) is added to neutralize the potassium tert-butoxide. The mixture isdiluted with 500 ml. of water and then extracted 3 times with 100-ml.portions of ethyl acetate. The ethyl acetate extracts are dried andevaporated to give a residue which is chromatographed over silica gel(elution with 5% ethyl acetate in Skellysolve B) to give afterevaporation of the eluates, 380 mg. of starting material (alpha) and 700mg. of the corresponding beta isomer.

Following the above procedure but using the beta isomer as startingmaterial, the same results are obtained.

I claim:
 1. A racemic compound of the combination of the formula:##SPC27##wherein the side-chain hydroxy is in S configuration, and themirror image of that formula; wherein R₁ is hydrogen, alkyl of one to 8carbon atoms, inclusive, cycloalkyl of 3 to 10 carbon atoms, inclusive,aralkyl of 7 to 12 carbon atoms, inclusive, phenyl, or phenylsubstituted with one to 3 chloro or alkyl of one to 4 carbon atoms,inclusive; wherein R₂ is --(CH₂)_(a) --CH₃ wherein a is 2, 3, 4, 5, or6, or --(CH₂)_(d) --X wherein d is zero, one, 2, 3, or 4 and X isisobutyl, tert-butyl, 3,3-difluorobutyl, 4,4-difluorobutyl, or4,4,4-trifluorobutyl; wherein R₃ and R₄ are hydrogen or alkyl of one to4 carbon atoms, inclusive; wherein A is trimethylene or --CH₂ --Z--wherein Z is ethylene substituted with one or 2 fluoro, methyl, orethyl; and pharmacologically acceptable salts thereof when R₁ ishydrogen.
 2. A racemic compound according to claim 1 wherein R₁ ishydrogen, alkyl of one to 4 carbon atoms, inclusive, or apharmacologically acceptable cation.
 3. A racemic compound according toclaim 2 wherein R₂ is --(CH₂)_(a) --CH₃ wherein a is 2, 3, 4, 5, or 6.4. A racemic compound according to claim 2 wherein R₂ is pentyl.
 5. Aracemic compound according to claim 3 wherein A is trimethylene.
 6. Aracemic compound according to claim 4 wherein A is trimethylene.
 7. Aracemic compound according to claim 3 wherein A is --CH₂ Z-- wherein Zis ethylene substituted with 2 fluoro on the carbon adjacent to thecarboxylate moiety.
 8. A racemic compound according to claim 4 wherein Ais --CH₂ Z-- wherein Z is ethylene substituted with 2 fluoro on thecarbon adjacent to the carboxylate moiety.
 9. A racemic compoundaccording to claim 5 wherein R₃ and R₄ are hydrogen.
 10. A racemiccompound according to claim 6 wherein R₃ and R₄ are hydrogen.
 11. Aracemic compound according to claim 7 wherein R₃ and R₄ are hydrogen.12. A racemic compound according to claim 8 wherein R₃ and R₄ arehydrogen.